The article I read this week was “Fish eggs can hatch after being eaten and pooped out by ducks”. I found this interesting not only because of the title of the article but also because scientists and researchers actually thought this topic was an important one to discuss. I found it interesting that even a few fish eggs could survive the stomach acids and the gizzard and that this was an open question for centuries according to Patricia Burkhardt-Holm. I also find it amazing that since fish eggs are soft and the bird feet, feathers, and feces can spread only “hardy plants seeds and invertebrates”, the eggs were still somehow able to make it through the gut. Even though only 0.2% of the eggs were intact, some were able to hatch. This is still an important step to answer the question of how bodies of water are so populated with fish. Birds that migrated could travel many miles before getting rid of the eggs which can transport the species of fish to many places. This will then allow for the population of fish to many areas because one carp can release “hundreds of thousands of eggs at a time”.
Today, I read the article, “How the Zebrafish got its stripes”. The article discussed animal patterns, which are the spots and stripes seen in nature. Researchers at University Bath have made a mathematical model in order to explain how the Zebrafish developed its stripes. Zebrafish, fresh water minnows, are used for studying human disease because they show many genetic similarities with our species. In addition, they also have several similar physical characteristics as us, including organs. The new mathematical model that was made by University Bath is critical to understanding pigment patterning systems, as well as their similarity between different species. The stripes of an adult Zebrafish are made from cells called chromatophores. As the animal grows, the pigment cells shift on the surface of the animal, and interact with one another to then self organize into the “stripes” pattern. Mathematicians have been trying to explain the forming of stripe on zebra fish for several years, however, the model made now has proven to be successful in predicting the development of pattern in both mutant and wild fish. In addition to this article, I also read, “A New Theory of Dreaming” by Neuroskeptic. The article discusses a new theory for why humans dream. Eagleman and Vaughn believe that we dream to make sure that the brain’s visual cortex is kept busy while we sleep. If not, the functions of the visual cortex may worsen over a period of time. However, their theory only makes sense if nueroplastic repurposing happens very quickly. Although, there is no evidence to show that these fast changes can be harmful to us. Both Eagleman and Vaughn’s theory would also predict that people who are vision-deprived would have less selective visual cortex, and so the REM disruption would strengthen this effect. In conclusion, these are the two article that I read today.
“How the zebrafish got its stripes” was a topic of great interest in the University of Bath, that a mathematical model was made to explain it. By studying their pattern formation it can help with the study of organ development and diseases. The mathematical model devised by the university discovered that the pigmentation in zebrafish is an example of an emergent phenomenon. This model can further explore a variety of pigment patterning systems in different species. Dr.Kit Yates, the mathematician who led the study, believes that the model will be able to highlight the rules that pigment cells use to interact with each other in order to generate patterns. Professor Robert Kelsh, co-author of the study, sees that by understanding the pattern development of a fish embryo they will be able to have a deeper insight into the choreography of cells in the embryo in a broader spectrum. The chromatophores, the pigment-containing cells, give the stripes of an adult ‘wild type’ zebrafish. The cells shift around on the animal’s surface and interact with each other and self-organise to make the striped pattern. Jennifer Owen, the scientist who built and runs the model, explains that thanks to the model it can help to predict the cell-cell interactions that are defective in mutants. Prior to having read this, I did not think much about how certain animals have a distinct pattern on their body. After having read this article it is shocking to learn how complex cells work. “A New Theory of Dreaming” offers a different perspective on why people dream. Eagleman and Vaugh’s theory: “The role of dreams is to ensure that the brain’s visual cortex is stimulated during sleep. Otherwise, if the visual system were deprived of input all night long, the visual cortex’s function might degrade.” The visual cortex, in the brain’s occipital lobe, can respond to non-visual signals if it is deprived of visual input. This is a form of neuroplasticity which is posed as a threat in Eagleman and Vaughn’s theory because it is not active all the time. In other words, dreams are our brain’s way of defending the integrity of our visual system by keeping it active. The author of this article does not buy this theory to be the main purpose of dreams. Eagleman and Vaughn do not hold any direct evidence claiming dreams are a defense mechanism against neuroplasticity and there is also no evidence that rapid neuroplasticity can be harmful. Eagleman and Vaughn show a correlation between the amount of REM sleep and the pace of development among primate species. The author suggests that the hypothesis, “the idea that faster development means slower neuroplasticity, and slower neuroplasticity means less need to protect the visual context from encroachment,” could be tested by conducting a controlled experiment. Overall, I think this theory is quite interesting because I always wondered why I dream at night. However, I wish that this article gave some insight about what our dreams mean and if there is an underlying meaning behind them. “Fish eggs can hatch after being eaten and pooped out by ducks” by Carolyn Wilke offers an interesting discovery that some fish eggs can exit the duck’s excrement, hence possibly helping to spread those fish to different places. Researchers have known that birds’ feathers, feet, and feces can spread hardy plant seeds and invertebrates but shockingly they never expected their feces to carry fish eggs because of how the journey of the egg includes the gizzards of the bird and an attack of stomach acids. Orsoyla Vincze, an evolutionary biologist at the Centre for Ecological Research in Hungary, and her colleagues led a lab where they fed 8,000 eggs to eight mallard ducks. The results showed that 18 ingested eggs were intact after defecation. After having just read the title of this article, I was so shocked and surprised that birds are an important vehicle for spreading fish. It is so surprising that some fish eggs are able to still survive and hatch after going through a bird!
The article “How the zebrafish got its stripes,” published by the University of Bath focuses on how the mathematical model developed to predict how stripes formed on zebrafish can be used to make scientific and medical advancements. Patterns are believed to have a strong correlation to organ development. This has caused some scientists to believe that by studying pigment pattern formation, they will be able to learn more about diseases that result from the disruption of an organ’s cell arrangements. Using this new information, they are hoping to make advancements in the medicines used to treat those diseases. Scientists hope that the mathematical model developed at Bath can be used to highlight the similarities in pattern development of different species. In zebrafish, pigmentation is an example of an emergent phenomenon, which is where cells function according to their own rules. This phenomenon was studied by Dr. Kit Yates who focused on how the model can reveal how pigment cells can produce specific patterns without coordinated centralized control. He believes that by studying this in zebrafish, discoveries can be made on the development of cells in fish embryos and embryos in general. Jennifer Own, who is credited with the development of the model, believes that due to the model's complexity, many revelations can be made on the development of embryonic cells. It’s crazy to think that huge scientific discoveries can be made based on studying the patterns of small fish. This realization will most likely set the precedent for future studies on the patterns of organisms who share similar organ structures to mammals. If the stripes of small fish can lead to a better understanding of embryonic development, it is very likely that more information is currently hidden in the patterns of other animals. Studying these organisms can give us a better understanding of the diseases that attack the organs of mammals. By analyzing the zebrafish and other similar creatures, perhaps we can come to some conclusions on possible medicines to treat these illnesses.
I read the article “How the Zebrafish got its stripes”. Zebrafish are actually valuable for studying diseases that affect humans. They show many genetic similarities and have similar physical characteristics, including major organs, to humans. Marine biologists believe that studying their appearance may, in time, be relevant to medicine , since their pattern formation is an important general feature of organ development. Professor Robert Kelsh, co author of this study explains, “ If we can understand what’s going on in the pattern development of a fish embryo, we may be able to gain deeper insight into the complex choreography of cells within embryos more generally.” I find it really cool that a simple thing such as a fishes’ stripes can help understand diseases caused by disruption to cell arrangements within organs.
In the article “A New Theory of Dreaming”, Neuroskeptic talks about a new theory proposed by David M.Eagleman and Don A.Vaughn called The Defensive Activation theory:Dreaming as a mechanism to prevent takeover of the visual cortex and how Neuroskeptic doesn’t accept this theory. The theory states that the role of dreams is to ensure the brain’s visual cortex is stimulated during sleep, and if the visual system were deprived of input all night long, the visual cortex’s function could degrade. Pretty much, the visual cortex starts to respond to non-visual signals if it doesn’t receive visual input. This change of function of under-utilized brain areas is known as a form of neuroplasticity. Neuroplasticity is usually considered a good thing, but Eagleman and Vaughn state that for our visual system, neuroplasticity can be very bad because our vision isn’t active at all times. Looking from this viewpoint, dreams are our brain’s way of defending the integrity of the visual system by keeping it active, therefore lowering neuroplasticity. Although Neuroskeptic believes that this is a unique and never talked about idea, he doesn’t believe that it isn’t the main purpose of dreams. Neuroskeptic talks about how this theory can only make sense is neuroplasticity repurposing of the cortex happens very quickly, and although the authors of the theory discuss evidence that rapid neuroplasticity can occur, they do not talk about how these changes are strong enough to harm. He also states how the authors don’t discuss any direct evidence for dreams serving as a defense for the visual cortex. He then continues by talking about the correlation between amounts of REM sleep and the pace of development among primary species, which was shown by the authors to prove that faster development means slower neuroplasticity, and slower neuroplasticity means less need to protect the visual cortex from encroachment. At the end, he discusses an experiment to help prove this theory. I personally believe this theory is very unique and interesting, and I like how people can have different viewpoints for the same theory and how they can back up their statements with a good amount of evidence. Neuroskeptic’s argument against this theory was very informational, and he does manage to prove his point very well. In conclusion, this article is great to read and it was fun to learn about an idea that can answer a question thought about for decades.
I read the article about dreams and it was quite fascinating. The understanding and knowledge of dreams is very limited and still something neuroscientist and psychologists still struggle to understand. There are new theories that come up from time to time but still doesn’t give an answer that everyone believes. This new theory that has emerged although has scientific evidence to prove its accuracy still has many rejected the idea such as the author of this article. The new theory has many holes and questionable statements that proves how little we truly know about dreams. The theory that Eagleman and Vaughn’s have proposed suggests that the brain projects dreams in order to stimulate the visual cortex during sleep so it doesn’t deteriorate. Although this hypothesis seems alright the author does not believe it. He says that dreams might be more complex and have a deeper meaning and purpose. I agree with the author. It is hard for me to believe that the only reasons dreams exist’s is to stimulate a part of the brain that isn’t used while sleeping. I think that dreams mean more and show a lot more than that.
In the article, “Fish eggs can hatch after being eaten and pooped out by ducks,” the topic of water birds being a form of transportation for fish eggs was discussed. A certain food for water birds is fish eggs. Usually, thousands of eggs are ingested by these birds at a time, and only a few of the eggs are able to survive being in the stomach of a water bird. In a study conducted by Orsoyla Vince and her team, they were able to find out that about 0.2 percent of eggs that were ingested were intact. Before the eggs are excreted by water birds, these birds can travel dozens or hundreds of kilometers, which would explain why certain fish are present in isolated water bodies.
The article “A New Theory of Dreaming” by Neuroskeptic informs readers of a new theory regarding the purpose of dreams. The theory, proposed by David Eagleman and Don Vaughn, states that dreams are necessary in order to keep the brain’s visual cortex stimulated. Without dreams, they believe that the visual cortex will become inactive and its function will degrade while sleeping. The function of the visual cortex is to process the visual information received by the eyes. When it is not properly functioning, the visual cortex will begin to process information that is non-visual. An example of this occurring is in blind people, where other senses, especially touch, stimulate the visual cortex in the occipital lobe of the brain. It is interesting that certain parts of the brain can adapt to changes and carry out a different function than intended. However, this form of neuroplasty can actually endanger the functions of the visual cortex. Vision is not active in the dark, so there is a possibility for the visual cortex to be rewired and only respond to other senses. Dreams, however, keep the visual cortex active while sleeping and when the brain is unable to receive visual information from eyesight. This information is explained further in a preprint of the theory proposed by Eagleman and Vaughn. However, Neuroskeptic is not completely convinced by this and points out a few holes in their theory, such as the fact that neuroplasty would have to occur quickly in order for dreams to act as a defensive mechanism. Although there is also not much evidence to back up this claim, it still seems fascinating that dreams could have the purpose to protect certain areas of the brain.
I read the article, “Do dreams exist to protect the brain's visual cortex?” I really enjoyed this article and found the author’s skeptical tone to be interesting. The author highlights a hypothesis posed by David M. Eagleman and Don A. Vaughn. The researchers believe that dreaming is used to protect the visual cortex from takeover. The author is intrigued but not fully convinced by the hypothesis. He agrees that the brain can respond to non-visual signals if it is deprived of visual input for a long period of time, but does not believe that this period of time could be as short as a few hours (the period which we are asleep for). This process is a form of neuroplasticity, and the author thinks that this theory should be further tested to understand the full effects of this process. He proposes a test where volunteers would be given a fMRI scan as a baseline, followed by half the subjects being blindfolded for 24 hours. Then, the subjects would receive another fMRI. If Eagleman and Vaughn are correct, the subjects who were blindfolded would have less visually selective visual cortex. Thus, this article is important in furthering the research of this hypothesis.
When I was younger I have always wondered where dreams come from, or why we have dreams. However, no one really knew the answer to my questions. Recently a new theory has been put forth by Dr. Eagleman and Dr. Vaughn. They claim that the human bodies form dreams in order to protect the visual system. It is known that other senses are heightened when people are deprived of visual inputs. During the night, the visual cortex is weak and can be taken over by other senses. This can be harmful since the ability for the visual cortex to function can be reduced. However, this theory seems to be challenged by the author of the article. The author claims that there is no evidence whether harmful nueroplasticity can occur within a few hours. Both Dr. Eagleman and Dr. Vaughn provide evidence that rapid neuroplasticity can occur, but the harmfulness of it is still unclear. They also discuss the relationship between development and amount of neuroplasticity. They claim that the amount of REM sleep is lower when the rate of development is higher in primates. This means that babies who learn how walk faster and those who mature faster, have less dreams than babies who take a longer time to learn. However, their hypothesis doesn’t have enough evidence as they could have used better methods of testing. The author of the article proposed an experiment with human volunteers. These volunteers would be given an fMRI scan before and after to note the change. Half of the volunteers would wear a blind fold for 24 hours to stimulate visual deprivation and the other half would experience disrupted REM sleep. Using the fMRI scans, experts can determine the affects of the visual cortex on dreams. This experiment must go through multiple trials in order to provide accurate and reliable information. I believe this one of the several reasons that humans have dreams. Although this theory seems slightly far fetched, it could be a breakthrough for all of the questions revolving around the origin of dreams.
The first article I read was “How zebrafish got its stripes” by Vittoria D’Alessio. The article was about the pigment-filled cells (chromatophores) coming together to form patterns on the zebrafish. The way that animals can achieve the patterns we see was under speculation until the University of Bath discovered calculations to justify the zebrafish’ stripes. Once scientists dug deep, they found fascinating information. The formation of skin coloring agent cells for animal occurs throughout the embryonic period of growth. They make patterned structures, a topis of specific importance to scientists like developmental biologists and mathematicians because these studies could help treat many diseases. There are many unseen similarities between zebrafish and humans, like major organs. These similarities could help medicine in the long run. If biologists study these animals and justify why things are, they can make modifications to the cell to prevent problems, if any. An example of this is pattern formation, which is a critical event in organ growth. The chromatophores (pigment-filled cells) act like a flock, or a school of fish; synchronized. They come together to form something larger than themselves. The streaks are a representation of the core stage of growth. Studying these streaks will let us explore the routine of the cell in embryo in common. The cells are moving while the species is growing, so interact with each other to create a certain pattern. As they are interacting with each other, mutations take shape and create other patterns like spots. What is surprising and so fascinating, is that these cells do not work for a centralized factor. I find it astonishing that something as simple as stripes, has such a complex, and concealed background. Numerous small parts, like molecules and cells, have come together to create these stripes on species, but humans still can’t explain it in detail.
The second article. “A New Theory of Dreaming” by Neuroskeptic, is about how the theory David M. Eagleman and Don A. Vaughn’s theory was invalid. Eagleman and Vaughn’s theory of the function of a dream is: “The role of dreams is to ensure that the brain's visual cortex is stimulated during sleep. Otherwise, if the visual system were deprived of input all night long, the visual cortex’ function might degrade.” A type of neuroplasticity is other sensors kicking in when another is unable to. This can be harmful to an already weak sensory tool since it won’t get the exercise it needs. The writer of this article, Neuroskeptic, doesn’t believe that Eagleman and Vaughn’s theory is the main function of dreams. One point that they make is within a few hours, damaging neuroplasticity would have to happen. On the other hand, dangerous neuroplasticity usually occurs in a long time, which doesn’t allow the sensory tools to weaken.
The third article I read was “Fish eggs can hatch after being eaten and pooped out by ducks” by Carolyn Wilke. I found this article especially interesting because it was something unexpected. This article was about how bird-dispersed fish eggs all over different bodies of water. Many biologists didn’t expect fish eggs to survive the digestive system of the bird since fish eggs are soft. The eggs surviving can explain things, like how the different and same types of fish are dispersed throughout one or many bodies of water. When some biologists were testing this, not many eggs survived, but it was still an impressive amount who did survive. Approximately 0.2 percent of eggs were eaten survived, which would be 18 out of 8,000. While the amount of intact eggs is low, their numbers can contribute to making bird feces crucial transportation for fish. Vincze, a biologist at the Centre for Ecological Research in Debrecen, Hungary, says a single fish can produce hundreds of thousands of embryos at a time. And there are large numbers of birds all over the world which can prey on those eggs alone.
The article that I read was “How zebra fish got its stripes”. Researchers at the University Bath have studied and have developed a model to explain how the zebrafish develops its strips. These species of fish are very important for studying the human disease. They have many genetic similarities to our species. Furthermore, we have many similar physical characteristics. The researchers believe studying their appearance may be relevant to to medicine. The reason is that the pattern formation is an important feature of organ development. Furthermore, the researchers want to better understand the pigment pattern formation, so they can give us insights into diseases caused by disruption to cell arrangements within organs. The new model created by Bath further explains the pigment patterning systems, and shows the zebrafish similarity to other different species. The stripes of the zebrafish is an example of an emergent phenomenon. Emergent phenomenon is when individual cells all act to their own local rules to form an ordered pattern. Dr. kit Yates from Bath explains how the model shows the local rules that these cells use to interrelate with each other to create these patterns.
I chose the article "A New Theory of Dreaming" for this week's post. This article was interesting to me since it addressed the mystery of dreams in the human species. The newest theory proposed by David M. Eagleman and Don A. Vaughn claimed that is dreaming is used for avoiding the visual cortex taking over. Furthermore, they noted that it is to make sure the "brain's visual cortex is stimulated". A consequence of the lack of input could be the degrading of the visual cortex. Some facts about the visual cortex are that it is located in the brain's occipital lobe, it responds to non-visual signals only when there is deprivation of visual input. The article mentioned that in blind people the occipital lobe will end up reacting to touch since there is no visual input. Eagleman and Vaughn also said neuroplasticity is a threat, neuroplasticity is re-wiring the less used places in the brain. They said this could be a possible threat because vision is not always active. The example they provided was if a person was in a dark place other senses may takeover, which is why dreams keep it active preventing the possibility of a takeover. The author mentioned that they do not agree with the theory, they mentioned dreams are associated with REM cycle of sleep which stimulates the occipital cortex. They also added that for the theory to be sound it would mean that the cortex is repurposed quickly. It said that humans have the most REM which leads to them maturing slowly than the rest of the primates. In the end the author mentions still more testing would need to be completed in order to make this theory more believable.
This week I read “A New Theory of Dreaming” by Neurosksptic. I really enjoyed the article because I never really understood why we dream in the first place. I believe that the theory was correct because it would make sense that dreams take place in order to keep our visual system active. I do understand why some people may not buy the theory, because there seems to be a lack of evidence in some areas. Lastly, I believe the hypnosis is a great idea because not only could it be tested easily, but it could answer all the questions that psychologists and neuroscientists have.
I've read the article on how zebrafish got it's stripes and when I read about the zebrafish getting their stripes, I have found something very fascinating about zebrafish that I had never knew about. The fascinating thing I had found in that article was that Zebrafish were used to study human diseases. Zebrafish have many genetic similarities and they also have a lot of physical characteristics such as major organs. They are very interesting to learn about in science because the show a lot of genetics similarities and physical characteristics to learn about for marine biologists. When I was still reading the article, the article states that " If we can understand what’s going on in the pattern development of a fish embryo, we may be able to gain deeper insight into the complex choreography of cells within embryos more generally." I find that very intellectual that learning from a very simple thing such as a Zebrafish's stripes can help with understanding diseases caused by disruption to cell arrangements within organs.
“A New Theory of Dreaming,” by Nueroskeptic explains The Defensive Activation theory in their opinion. Before this theory was explained, many psychologists and neuroscientists did not have a solid answer to the question, why do we dream. David M. Eagleman and Don A. Vaughn proposed the Defensive Activation Theory. In the article, this theory is defined as dreaming as a mechanism to prevent takeover of the visual cortex. Nueroskeptic states that they think it’s a highly original and creative theory, but he/she isn’t completely convinced. Eagleman and Vaughn’s theory is stated in the article like the role of dreams is to ensure that the brain's visual cortex is stimulated during sleep. Otherwise, if the visual system were deprived of input all night long, the visual cortex's function might degrade. The visual cortex is the brain’s occipital lobe. This lobe starts to respond to non-visuals signals if there is nothing visual in its input. The article provides an example of blind people. Due to the fact they can’t see, their occipital lobe responds to touch. The rewiring of the brain from sight to touch is a form of neuroplasticity. Neuroskeptic explains that neuroplasticity is generally good, but Eagleman and Vaughn believe that for visual systems, neuroplasticity can be posed as a threat. This is because vision is a sense which is active all the time. If people are in a dark place, like at night, there is no visual input, thus our visual cortex would be able to have another sense takeover in that time of vulnerability. So, due to the theory, when we dream, it’s the brain’s way of keeping visual systems alive. Neuroskeptic doesn’t buy this theory because dreams go hand in hand with simulation of the occipital cortex during a stage when sleeping called REM sleep. So, yes, dreams stimulate one’s visual system, but it is not their only job. Eagleman and Vaughn’s theory can also only make sense if neuroplasticity repurposing a visual sense to another sense happens rapidly. For the visual cortex to be defending neuroplasticity, the process would take a few hours. Eagleman and Vaughn do discuss evidence which can explain rapid neuroplasticity, but there is no evidence which shows that the rapid changes are strong enough to be harmful. They also show a correlation between the amount of REM sleep and the pace of the development of primate species. Primates whose babies tend to learn to walk and mature faster have less REM sleep. Thus, humans have the most REM, due to us being the slowest maturing primates. Basically, the faster the development, the slower the neuroplasticity, which means less of a job to protect the visual cortex from encroachment. The authors cite indirect evidence which states, “The present hypothesis could be tested thoroughly with direct measures of cortical plasticity.” Neuroskeptic believes that the hypothesis can be tested easily by taking human volunteers for a fMRI scan, at baseline, to establish the extent of their visual cortex and how visually selective it is. For 24 hours, half the volunteers would be blindfolded to produce visual deprivation. Half would have REM sleep disrupted that night, as well. At the 24 hour mark, they will get another fMRI scan. The author’s theory would predict that vision-deprived people would have a less visually selective cortex and the REM distribution would heighten this effect.
This week I read the article titled “Fish eggs can hatch after being eaten and pooped out by ducks”. It was interesting to say the least. I had never really thought about invasive species being spread through excrement, but this new study demonstrated it as a possibility. In Hungary, Orsolya Vincze, a biologist, and her team conducted an experiment involving thousands of carp eggs and eight mallard ducks. They discovered that 18 of the 8,000 eggs survived the journey through the ducks and remained viable in the ducks’ droppings. This was quite unexpected mainly because of how soft fish eggs are. Although it’s an oddly interesting discovery, this proves to be problematic because some carp species, like the ones the scientists fed to the ducks, are invasive species. As mentioned in the article, one carp can release thousands of eggs at a time, and there are a lot of water birds that are willing to feast on those eggs, making them a major method of transport for invasive fish species. The other article I read discussed the new theory of dreaming. The article opens with the statement about the function of dreams and how it still remains a debate to this day. David M. Eagleman and Don A. Vaughn are then introduced along with their new theory about the purpose of dreams. Basically, they believe that dreams serve as a defense against neuroplasticity by keeping our visual system active so it’s not taken over by other senses. In other words, dreams occur to ensure that the brain’s visual cortex is stimulated while we sleep to prevent the degradation of the visual cortex’s function. This article was intriguing, and although I’ve never really pondered this question of what dreams do, their theory is quite thought-provoking. However, the author of the article expressed their disbelief of Eagleman and Vaughn’s theory. They argue that the theory only makes sense if neuroplasticity occurs both rapidly and harshly enough to actually do damage to the visual system. After reading the article, I began thinking about how many unanswered questions about ourselves remain and how interesting it can be to read about possible explanations to these questions.
The article I read today explained about different theories on why or how sealife, or “Zebrafish”, got their stripes. Many experiments have been done already to attempt to find a rationalization on this observation, and eventually there were propositions that there are certain pigments that spread more rapidly compared to other pigments in other wildlife. The spreading of pigments catches the concern of medical doctors because certain observations about pigments, stripes, dots, or any patterns on the bodies of sealift could result in new research for the medical field. Studying the outer bodies of the Zebrafish’s striking appearance may be relevant to medicine, since pattern formation is an important general feature of organ development, which can help treat diseases in the future.
The article “How the zebrafish got its stripes” informs the reader of the mathematical equation created by the University of Bath used to explain the origin of the fascinating stripes on zebrafishes. The article begins by discussing how animal patterns are generally created. It states that the arrangement of skin pigment cells starts during the embryonic stage of development which raises the attention of developmental scientists and mathematicians. Regardless of having little in common with mammals, zebrafish surprisingly have similar physical characteristics with humans such as major organs. This similarity is very critical as the information discovered relating to the pattern formation of a zebrafish could pave the way for future medical advancements involving diseases caused by a disruption to cell arrangements within organs. By specifically exploring the pigmentation of zebrafishes, and the singular movements of their cells scientists find it riveting that these same cells can form the zebrafish’s stripes during their embryonic stage. After understanding the pigmentation and how it is an emergent phenomenon, mathematicians at the University of Bath formed a mathematical model that could better understand pigment patterning systems, predict the pattern development of both wild and mutant fish and explore their similarity across different species. This equation has provided legitimate results and has cleared up some confusion regarding whether the zebrafish's unique cell movement relates to the formation of animal patterns. To conclude, the cells that form the interesting stripes on a Zebrafish have proven to be very impactful to the study of pattern formations as a whole.
The first article that talked about how zebrafish got their stripes, was shocking. Before, I did not know that patterns were anything more than different tones of pigment. First, I learned that in the animal kingdom, the arrangement of skin pigment cells starts during the embryonic stage of development, making pattern formation an area of interest for scientists and researchers. I did not realize before that scientists had to start at the very first stage of fish development. I also did not know that zebrafish have genetic similarities to humans, despite not being mammals. Studying zebra fish's patterns are important because pattern formation is important to organ development. A better understanding of pigment pattern formation might give us insights into diseases caused by disruption to cell arrangements within organs pigment in zebrafish is an example of an emergent phenomenon, where cells can act according to their own individual rules, including self organization which leads to patterns. It is astonishing how scientists all over the world can use the zebrafish's embryo to analyze the choreography of cells. Stripes of an adult 'wild type' zebrafish are formed from pigment containing cells called chromatophores. Within the three types of chromatophores, all types shift around (self organization). I also learned how important it was to analyze data. Mathematical models can be used to incorporate the 3 cell types, and can predict the pattern development of future zebrafish.
The second article discussed a new theory of dreaming. Created by Eagleman and Vaughn, it states that the role of dreams is to ensure that the brains. Otherwise, if the visual system were deprived of input all night long, the visual cortex function might degrade. I have read many theories on why we dream, and this one was definitely intriguing and unique. To me, it made sense as our body has multiple defense mechanisms to keep us healthy. New study shows that neuroplasticity (the ability of the brain to form and reorganize synaptic connections, especially in response to learning or experience or following injury) could actually pose a threat because vision, unlike other senses, isn’t active all the time. Dreams could be our brains' way of defending the integrity of our visual system by keeping it alive. This means our visual cortex will never be “off”, and our visual sense would not degrade. The theory would only make sense if neuroplastic repurposing of the cortex happens very quickly, and there is no evidence to show that. In fact, there is barely any evidence to show that dreams are defense mechanisms for our visual cortex.Slower neural plasticity knees less need to protect the visual cortex, since only faster neural plasticity can invade. Overall, this theory was quite interesting, but I believe that there should be more evidence to support this hypothesis. Perhaps even an experiment could be involved.
The last article discussed how fish eggs can be hatched after ducks have eaten, then released them through the feces. I find it astonishing that fish eggs can enter, and be released from, a body and still be alive. According to a study done with mallard ducks and carp species, only 0.2% of the species were intact. Although only so little still remained alive, I am fascinated by even that percentage. Before, I had always thought that since fish eggs were soft, they would easily die in a duck’s guts.
In the article « A New Theory of Dreaming » the author introduces Eagleman and Vaughn’s idea about why people dream. Eagleman and Vaughn believe that dreaming is a mechanism used to prevent the takeover by the visual cortex during the time that the visual cortex is not otherwise stimulated. The author isn’t entirely convinced by this theory, they point out that neuro plasticity — which is when the occipital lobe is able to retire itself due to the deprivation of vision — is not considered to be harmful. See the theory only would apply if the neuroplastic repurposing of the cortex occurred quickly and at that rapid rate, the effects would need to be at a rate to cause serious harm. The known relation between dreams and the occipital cortex is that they occur during REM sleep. This means that dreams do stimulate the visual system, but there is no evidence as to whether or not its actual purpose is to protect the visual cortex. There is a potential experiment that can be done to test their theory though. They could use a group of human volunteers and observe their initial functionality of their visual cortes and then for 24 hours disrupt the REM sleep of half of them to see the differences in their visual cortex functionality.
I found the article, “A New Theory of Dreaming,” particularly interesting. As addressed by the article, dreams occur during REM (rapid eye movement) sleep. During this stage of sleep, your EEG, or brain waves, are similar to that of when you are awake, as well as some physiological functions such as heart rate and breathing. The only difference is your muscles are virtually paralyzed, which is how sleep paralysis occurs (when you wake during this stage, your mind enters a conscious state, but your body is still in a state of paralysis). There is not much difference in this stage that can account for neuroplasticity to occur other than the fact that there is a lack of visual stimulation. The researchers do bring up an interesting point about the functioning of the occipital lobe in the visual cortex, as it is usually correlated with vision, in blind people it is correlated with touch. When blind people dream, their perceptual experiences are usually not visual, which supposedly supports Eagleman and Vaughn’s theory that dreaming prevents the degradation of the visual cortex, and can lead to new pathways being formed to adapt to the minimal use. However, if the brain enters this cycle when you sleep, wouldn’t that be an indication that there is no need for the brain to adapt because it already alters its state when you sleep? Sleep is a part of the circadian rhythm that organisms possess, so it is a natural cycle. The brain might be used to when it falls into the sleep cycle so there would be no need for there to be a change in the neural pathways and synapses. It is an interesting theory, though I don't think it is the most plausible for the reason why we dream.
This week I read the article, “Fish eggs can hatch after being eaten and pooped out by ducks” by Carolyn Wilke. After initially reading the title I was immediately interested, but I didn’t realize how this discovery could have potentially solved the mystery of how isolated bodies of water become populated by fish. As the article says, fish eggs are really soft and it seems crazy to think that any could survive the acidic digestive tract of a duck, but the fact that 18 out of 8000 did in an experiment conducted by Orsolya Vincze shows that it is a possibility in the wild. I wonder if these eggs that remained intact will develop normally, or if there will be any problems with the fish as they grow. I would love to see this experiment be done with different species of fish to see if different fish eggs have a greater or lesser chance of surviving digestion, or if there are certain circumstances that increase an egg’s chance of survival. While reading about ducks pooping out eggs was interesting, the fact that it possibly explains how fish reach isolated waters is what truly amazed me.
This week I read “How the zebrafish got its stripes''. Overall the article spoke about the skin pigmentation cells and how they can be mutated making different patterns. The arrangement of these skin pigment cells begins in the embryonic stage. These arrangements create patterns, formations, and specific areas on the skin of animals. The zebrafish are used to study human diseases due to their genetics and major organs being so similar to humans. By understanding their appearance, it may help us understand diseases caused by disruption to cell arrangements within organs. Dr. Kit Yates explains how the different pigment cells act without coordinated centralized control, yet the cells still produce the stripe pattern on the zebrafish. These stripes are an example of a key developmental process and can help us further understand the complex choreography of cells while in the embryos. When mutations do appear they create a leopard, spotty, or labyrinthine pattern. I find this article interesting and would love to learn more about the zebrafish studies and theories. I wonder how the mutations the zebrafish has relates to what happens to us. I would like to know more about how the pattern might look if they’re in different parts of the world, environments, and more.
When deciding which article to read, the one titled “Fish eggs can hatch after being eaten and pooped out by ducks” instantly caught my attention. After reading it, it actually proved to be very informative as well as interesting. The discovery of fish eggs being able to survive after being eaten by ducks could be one of the ways isolated bodies of water can be populated by fish. This puzzled scientists for a very long time, as there’s no way for a fish to find its way into such a body of water. This discovery finally gives researchers a reason why fishes got there, because ducks can fly to other locations and poop the fish eggs out. The eggs could stay in the ducks body for up to 4 hours. In this time, the ducks could travel huge distances, and get to remote bodies of water. After further experimentation, it was found that .2% of eggs eaten by a mallard duck can survive and possibly hatch. Even with a low success rate, one fish can hatch many more fish, and populate a body of water easily. The possibility of this was disregarded prior to this research due to a fish egg’s soft shell. It was believed they’d be too fragile for such a possibility. This phenomenon proved that thought wrong, and showed me once again how complex and amazing nature really is. If I hadn’t read this article, I wouldn’t have known such a thing could happen.
The article "A New Theory of Dreaming", by Neuroskeptic discusses a newly proposed theory on why we dream. The author of the article finds the new theory proposed by David M. Eagleman and Don A. Vaughn interesting, but not fully convincing. The theory is mainly focused around the idea that the role of dreams is to ensure that the visual cortex in our brain is still active while we are sleeping. If it isn't active in our sleep, then the function might degrade. If the brain's occipital lobe, where the visual cortex is located, doesn't get any visual input, then it is prone to be taken over by our other senses. For example, blind people have an occipital lobe that strongly responds to touch because it lacks visual input. If the brain repurposes areas that arent utilized a lot, neuroplasticity happens. Neuroplasticity is mostly a good thing because the parts of the brain that we do not use a lot to develop a new role which will benefit the organism positively. However, the theory states that for the visual system neuroplasticity may be harmful. This is because unlike our other senses our vision isn't active all the time. For example, in the night or a dark place, we receive slight or no visual input. Therefore, dreams in a way keep this part of our brain alive so neuroplasticity does not occur. The author of the article then mentions that even though this theory is true, it may not be the main reason why we dream. Dreams are associated with the stimulation of the visual cortex during a stage called REM sleep, so they do help keep this part of our brain alive. However, neuroplastic repurposing does not happen very quickly. For the visual cortex to be in danger, harmful neuroplasticity would need to occur in the time frame of a few hours. Although the authors of the theory do include evidence to prove that rapid neuroplasticity can occur, they don't provide any evidence to show that these changes are powerful enough to be a threat. The theory does not include any evidence that shows that dreams act in defense. Instead, they claim there is a correlation between the pace of development and the pace of neuroplasticity. Primates who mature faster or develop faster have a smaller amount of REM sleep, and primates who mature slower have more REM. Humans are slowest maturing primates, so comparatively have more REM. Therefore, if the organism develops quicker, they have slower neuroplasticity which, means that they have less of a need to protect the visual cortex. The author of the article claims that this statement is purely circumstantial. She also mentions that the theory could be further tested with an experiment. If you take a group of human volunteers and give all them an fMRI scan to see the extent of their visual cortex, and then proceed to blindfold half of them for 24 hours, you could compare the visual cortex abilities of both groups with another fMRI scan. Eagleman and Vaughn's theory should show that the blindfolded group has less of a visually selective visual cortex and that the REM distribution enhanced the effect to be proven correct. In summation, this article was very interesting to read and I would like to see further results of this theory.
This week, I read the articles “A New Theory of Dreaming” by Neuroskeptic, and “How the zebrafish got its stripes” by the University of Bath
The first article discusses a new theory about why we dream. This theory by David M. Eagleman and Don A. Vaughn is from a preprint article which is a scientific paper that has not gone through peer review, which could make the paper inaccurate. Nevertheless, this theory is interesting.Researchers behind the theory believe that dreams are used to keep the visual cortex stimulated to prevent it from degrading. The article also discusses Neuroplasticity, which is when an underutilized area of the brain is repurposed. An example from the article pertains to blind people. Since blind people do not use the visual cortex, which is in the occipital lobe, the occipital lobe is rewired to respond to touch. In most cases, Neuroplasticity is a good thing, but when it comes to vision, it is not. Vision isn’t active all the time, which means it is at risk of being repurposed. Dreams help prevent this by simulating the occipital lobe when vision is not active. The author does not completely agree with this theory, and makes some valid points against it. For example, he says that for the visual cortex to need defending,Neuroplasticity would have to occur quickly. Although there is evidence that supports this, there is no evidence that shows it is harmful. They also discuss an experiment to test this new theory. The experiment requires a group of human volunteers to get a FMRI scan to use as a baseline for how selective the visual cortex is. The volunteers are blindfolded for 24 hours to simulate visual deprivation, and half the volunteers have their REM sleep disturbed. At the end of the experiment, another FMRI scan will be made. If the theory is correct, then the data from the second FMRI scan will show that the participants have a less visually selective visual cortex at the end of the experiment. This article got me interested in Neuroplasticity. I specifically thought about how neuroplasticity may relate to natural selection and evolution. Since neuroplasticity is a change in brain function as a result of external conditions, it is in a way a method of adaptation. Natural selection says that organisms better adapted to an environment survive longer, and reproduce, passing on desirable characteristics to offspring, and causing evolution over generations. Neuroplasticity causes our brains to evolve. This is explained in the paper “Allocating structure to function: the strong links between neuroplasticity and natural selection” written by Michael L. Andersen and Barbara l. Finley.
The second article discusses how researchers at the university of Bath created a mathematical model to explain how zebrafish got stripes. This study is very important, since they have genetic similarities with humans, and they also have most of the same organs we have. This study may also have implications on medicine, since pattern formation is important to organ development. It will help us understand the choreography of cells in the embryo. The article discusses how zebrafish stripes are caused by emergent phenomena, where individuals acting on their own rules are able to form a pattern. Examples of this include fish swimming in schools and sparrows.This phenomenon enables us to know exactly the process that is happening. In zebra fish, the pigment cells called chromatophores create the pattern without having a centralized control. The model predicts the development of the pattern by using information about the three chromatophores and their interactions. Their model can also be used to predict the pattern development in fish with mutated genes. Although there have been other attempts to create a similar model in the past, the other models were not able to account for mutations like the one created by the Bath University. Jennifer Owen, one of the scientists who created the model explains that the complexity of the model is the reason why it can predict the interactions between the cells of mutant fish.
This week, I read the first two articles provided. I found both articles very enjoyable to read, as they dive into very interesting topics that aren’t as important as the major events going on today. I found the first article, “How the zebrafish got its stripes” very fascinating and I was surprised that researchers are just finding this out in the present day. I was very astonished to learn that zebrafish have many genetic similarities to humans and include many similar physical characteristics, including most major organs. This is considering that this species looks completely different from our species, so it is difficult to identify them as similar. Also, studying the appearance of the zebrafish may be relevant to medicine in the future, by relating to their unique pattern, and may give a closer look into diseases that are caused by disruption to cell arrangements within organs. A new mathematical model helps to further explore pigment patterning systems. The pigmentation in zebrafish is an example of an emergent phenomenon, where cells can self-organize to form an ordered pattern at a much larger scale. There are many more examples of this in other parts of nature and biology. Dr. Yates, a mathematician who led the study, was fascinated by this discovery and states how the models can show the rules used for the cells to carry out their self-organization. Professor Kelsh, a co-author of the zebrafish study, had stated that it was important to find a correct mathematical model to explain the stripes on zebrafish because they are an example of a key development process. Precisely, if they can understand what occurs when the patterns develop when the fish is an embryo, then they will obtain more information on the complex choreography of cells within the embryos. Scientists have concluded that the stripes of a zebrafish are formed from pigment-containing cells, called chromatophores. These cells shift around the fish’s surface as they develop, and the cells interact with one another to create the patterns. When mutations occur in the cells, they result in distinct markings. I also read the article, “A New Theory of Dreaming”, which I found relatable, as I also wonder of the question of “Why do humans dream”. There have been many theories to answer this question, although there has been no accepted answer for centuries. Two researchers, David M. Eagleman and Don A. Vaughn, have proposed a new theory stating “The role of dreams is to ensure that the brain's visual cortex is stimulated during sleep. Otherwise, if the visual system were deprived of input all night long, the visual cortex's function might degrade.” Although neuroplasticity is considered a good thing, the two scientists express the fact that neuroplasticity could actually pose a threat to the visual system. This is because vision isn't active all the time (like when we are sleeping or in a very dark place), unlike our other senses. So, the visual cortex will produce dreams to keep the visual system active. I think this is a fascinating theory and it seems correct, but I am not very experienced in this topic, so the author doesn’t believe it. They express this by stating all the data that Eagleman and Vaughn haven’t provided and how there are missing points in the theory. The author also states that this theory can be tested easily by carrying out an experiment with human volunteers. From these articles, I have learned a lot about current events going on in the world that do not involve the global pandemic.
In the article “How the Zebrafish got its stripes” the University Bath has begun using a mathematical model to represent how Zebrafish obtain their striped pattern. This fascinating process is being studied by both developmental scientists and mathematicians to create this mathematical model. Scientists have discovered that the formation of this pattern occurs during the embryonic stage through skin pigment cells. They have found that the Zebrafish have a lot of physical characteristics that are similar to mammals, specifically similar organs. Due to the similar organ development scientists are looking into the pattern formations in relation to medicine. By knowing how the pattern forms in Zebrafish, scientists can have a better understanding of diseases in the organs that are caused by the disrupted cell arrangements. Overall the University Bath is fascinated by the phenomenon in which individual cells of the Zebrafish interact and arrange the striped pattern without a central control. The striped pattern is formed from cells called chromatophores that shift around and organize the pattern. However when mutations occur the cells do not probably interact and cause a spotty pattern. Understanding how this phenomenon works and the effects of mutations is a key part of understanding the developmental process which could be relayed to other species embryos.
Today I read, “Fish eggs can hatch after being eaten and pooped out by ducks” by Carolyn Wilke. After reading the article, I was shocked to learn that some fish eggs are able to incubate even after they are consumed by another animal. This was completely unexpected because I thought that the acid inside of the duck’s stomach would prevent this from occurring. One might think that it would be a bad thing for these ducks to consume these eggs because it could lead to a decrease of the fish population. In actuality, it helps spread their species to new isolated bodies of water that the fish would have been previously unable to reach. In addition, the spread of these eggs creates new food sources for other animals which allows new ecosystems to form and grow. Although the spread of fish into new environments can be beneficial, it is not always. For example, if you have an invasive species, such as a Common Carp, it could destroy the entire ecosystem. Any time a new species is added into an environment, the whole food chain could become disrupted. Overall, I found the article very informative and it makes me wonder if it is possible for other eggs to survive an animal’s digestive system. For example, if a snake ate a bird egg, would the egg be able to hatch after being processed through its digestive system? Only further research and observation can answer these questions.
I read the article of "A New Theory of Dreaming", and I was very fascinated by it. Eagleman and Vaughn's theory of the sole/main purpose of dreaming is that it is to prevent the takeover of the visual cortex of the brain due to neuroplasticity. This theory is incredibly interesting and might hold some truth to it, especially when they mentioned how a blind person's dreams are like. However, it does not seem to answer why our dreams are so extravagant and weird and why we get nightmares. If the sole purpose for dreams was so that we continue to have our visual cortex, why do we dream about living in different planets with mythical creatures or dining with the gods or being royalty in the midst of an alien war? Why do we have such weird and unique dreams that are both impossible and not real at all? I can tell you with firsthand experience that I have never seen a 5 eyed ogre-vampire hybrid, yet here I am dreaming about going on a duel with it to gain the attention of the royalty. Why do we need to get these dreams when the only purpose of it is to save the visual cortex? I can just as easily solely dream of my experiences and different paths each experience could have taken (which I do, but it isn't the only thing I dream about,and for me, it is the minority group of my dreams). How does me dreaming about an ogre-vampire hybrid benefit my visual cortex in any way. In addition, why do we get nightmares? The brain's purpose is to maintain the survival of the human, making sure that our heart beats blood, that our lungs take in air to breathe, that we get food into our stomachs to digest. A part of survival is mental health, and a healthy brain is one that has no imbalances in neural molecules, making the human relatively happy for the most part. We do not like bad things to happen to us and experience bad experiences; in fact, we go out of our way to avoid such traumas. However, nightmares seem to do the exact opposite. They bring out your worst memories and replay them in worse paths or they take a completely new experience that you have never experienced and enhance it to make you scared while you cannot do anything but sit back and watch it all happen to you. What is the use and purpose of nightmares and purposely damaging your mental health for a night when according to the theory above, we only have these to protect our visual cortex. Is it really necessary for me to experience a horrifying nightmare to protect that part of my brain? I highly doubt it. Because of both of the reasons I said above, I disagree with Eagleman and Vaughn's theory for why we dream albeit how interesting it may be.
I chose to read “A New Theory of Dreaming” by Nueroskeptic because the consciousness is something I enjoyed learning about in psychology last year. In class, we learned about the “activation-synthesis theory” stating that dreams occur because the hindbrain is activated during REM sleep and the cortex tries to make sense of these signals. On the other hand, David M. Eagleman and Don A. Vaughn propose their “defensive activation theory”: dreams are needed in order to ensure that the brain's visual cortex is stimulated during sleep. Otherwise, if the visual system were deprived of input all night long, the visual cortex's function might degrade. They think that due to the brains neuroplasticity, the occipital lobe containing the visual cortex will take on a new function. As pointed out in the article, this theory has a few flaws, as it suggests we would be losing function in our occipital lobe during the nighttime, since all we see is black so the visual cortex isn’t simulated. Additionally, the only evidence given for the defensive activation theory was that the correlation between pace of an organisms development and the percentage of time spent in REM sleep. However, when observing the scatter plots detailing the correlation between amount of REM sleep and the pace of development among primate species, I observed the coefficient of determination to be especially low at 0.32 and 0.17, meaning only 32% and 17% of the observed variation between the pace of development and present of sleep spent in REM sleep can be explained by the model's inputs. Therefore, the correlation that was regarded as evidence for this theory is actually very low, and does not do a great job of proving said point.
This week i read, “How the Sebrafish got its stripes.” scientists can study the pigment pattern formation of a zebrafish’s stripes to further understand disease that disrupt cell arrangement in organs. The cells that create these stripes are an example of an emergent phenomenon, hence they could act at their own will (independently). The chromatophore (pigment cells) organize themselves into the distinct stripes that we know today by interacting with the cells around them. But why is learning about the development of zebrafish stripes important? It is important because we can learn from fish embryos and apply that knowledge to embryos in general, including our own. something i found interesting was when their chromatophore mutated, they create more of a leopard/ dotted pattern. Luckily, the new model from the University of Baths accounts for these mutations to produce the best mathematical model possible.
In this week’s article, “How the zebrafish got its stripes”, researchers at the University of Bath created a mathematical model to describe how zebrafish actually develop their stripes. Throughout the article, there are many different facts and insights given about zebrafish. The one that I thought was most interesting was that studying their appearance and going more in depth with the research can help with medicine since zebrafish have many similarities with humans, including major organs. I found this interesting because even though they aren’t mammals they still have many genetic similarities with mammals that can help with medicine discoveries in the future. The mathematical model that was created in Bath is capable of discovering pigment patterning systems and similarities between different species. The mathematician that led the study into the development of a zebrafish’s stripes, Dr. Kit Yates, states how different pigment cells act without coordinated centralized control to produce the stripes that are on zebrafish. It is important for researchers to find an accurate mathematical model because the stripes are an important part for a developmental process. The pattern development can help give more insight on what is going on in the complex cells in fish embryos. Overall, in this article there were many unique and interesting facts stated about the zebrafish. With further development, there could be more discoveries made with different species that have similarities compared to the zebrafish which could help with other findings in other animals. The other article I read,“A New Theory of Dreaming”, informs readers about a preprint article that was written by David M. Eagleman and Don A. Vaughn suggested that dreaming was a mechanism to make sure the brain’s visual cortex is stimulated during sleep. They suggest that without dreams the visual cortex’s function could possibly reduce. The author talks about how neuroplasticity is usually a good thing but Vaughn and Eagleman’s research contradicts that statement. They claim that it can be a threat since it isn’t active all the time. Neuroskeptic claims that the theory doesn’t seem valid and there should be more research done before deciding that it is in fact accurate. Neuroskeptic proposes that the hypothesis that faster development means slower neuroplasticity which means less need to protect the visual cortex from encroachment could be tested by using human volunteers and splitting the testing in half. This article was interesting since there has been so much speculation about dreams but not one definite answer. This article just proves that point since both Vaughn and Eagleman’s theory was predicted to be invalid. Both of the articles were interesting and unique compared to other articles in the news about COVID-19.
I read the article, “A New Theory of Dreaming,” and found it to be extremely interesting. Written by Neuroskeptic, this article discussed a theory that David M. Eagleman and Don A. Vaughn proposed. They expressed that dreaming was enacted to ensure that the visual cortex didn't take over. This theory came to be because dreams cause the visual cortex to be stimulated during sleep and if not, its function wouldn't stay as sharp. The visual cortex responds to non-visual signals when deprived of forms of visual input, and the rewiring is considered a form of neuroplasticity. Eagleman and Vaughn thought that neuroplasticity could be looked at as a threat or dangerous and vision isn't always active. They went on to express that vision isn't active at night, therefore dreams are a way to preserve the visual system by keeping it activated while asleep. The author expressed that he liked the creativity of the theory, but was opposed to the idea that the stimulation of the visual cortex was the sole reason that dreams took place. The author believes that for harmful neuroplasticity to occur and the visual cortex to need defending, it would have to happen in a span of a couple hours. They weren't convinced that Eagleman and Vaughn showed evidence that these changes were harmful to that extent, and none of their evidence supports the idea that dreams occur out of defense. The author proposed an experiment to see if their theory was true or not, by observing a group of volunteers’ sleep. Each of them would have their visual cortex scanned and half of the volunteers would be woken up during the REM phase of sleep. Their visual cortex would be scanned, again. They would then be able to measure whether those who were woken up would have a less selective visual cortex. This theory was very interesting to read about, and I liked getting the opposing standpoint of the author as well. I think my views align with the author, in the sense that their theory sounds good, but it doesn't make sense that dreams occur solely out of defense.
This week, I read the article titled "How the zebrafish got its stripes" from the University of Bath. The article discusses the creation of a mathematical model to explain and predict natural phenomena, relating to pigment patterns, and its importance to the overall interactions within an embryo at a cellular level. A key barrier to success with previous mathematical models was the possibility of mutations, which would change the interactions between pigment-producing cells and result in spots or labyrinthine markings. In zebrafish, three types of pigment-producing cells are key to their much-studied patterns. Two of these such cells are melanocytes, which are composed of black melanin, and xanthophores, which contain yellow and orange carotenoids. The third type of pigment-producing cell is iridescent iridophores (S-iridophores are relevant to stripe formation, whereas L-iridophores maintain the pigment pattern) composed of reflective platelets (Hirata et al., 2003). Mutations amongst any of these cells could affect the self-organization process, resulting in altered pigment patterns. With the creation of this model, scientists can take into account the wide variety present in nature and continue to understand rarer pigment mutations. Since zebrafish and humans share 70% of their genetic material, it's logical that utilizing zebrafish as a living model can help researchers understand a multitude of human diseases related to pigmentation such as melanoma.
The first article I read was “How the zebrafish got its stripes.” Upon first reading the article, I found it crazy that tiny little minnows, such as zebrafish, have several similarities with our species (such as the major organs). Although this study is interesting, it might not seem purposeful. In reality, the study of the formation of patterns in certain mammals is extremely useful, as pattern formation is a feature that is prominent with the development of certain organs. Therefore, this study can further provide information about organs and diseases that possibly develop with growth. University Bath created a mathematical model in order to further understand pigment patterns. The stripes of a zebrafish are an example of an emergent phenomenon, according to the article, which means that a zebrafish’s cells act according to their own regulations yet still self-organize into a much bigger pattern unintentionally. The mathematical model is important because it highlights an important step in the embryo development which leads to these pigment patterns. The article talks about chromatophores, which are cells that arrange to form the stripes of a zebrafish. As the fish grows, these cells further organize themselves into the prominent pattern which the fish is named after. It is known that the zebrafish’s pattern occurs because of the three types of chromatophores which self-organize. I did not see an importance of creating a model for why the zebrafish has stripes, but after reading I understand that the model can help understand mutations that can occur within the cells of zebrafish. I never really gave much thought to the process of how patterns form on any animal, not just zebrafish, but the intricacies of how these patterns form are interesting. The second article I read was “Fish eggs can hatch after being eaten and pooped out by ducks.” Despite the strong acid and the long journey experienced by fish eggs swallowed by ducks, some eggs are able to survive and therefore hatch. Although at first glance this study might seem pointless, it is one of the reasons that can contribute to why fish are found in certain remote bodies of water. It is mind boggling to me that people are creative enough to perform a study to find out if this is a contributing reason as to how isolated bodies of water have fish in them. Thinking logically, it makes sense though, considering ducks can travel several kilometers before the fish eggs are excreted. In the study, only 18 eggs hatched out of the 8,000 which may not seem like a lot in the grand scheme of things, but over time and with multiple ducks, it would add up. I thought fish eggs were fragile and definitely not strong enough to surpass a duck’s system, but clearly according to this article I was wrong.
The first article I read this week from the University of Bath entitled “How the Zebrafish Got its Stripes” informs readers about a mathematical model that researchers have developed to see how this species forms it's stripes and how this information can be used in beneficial ways in the medical and scientific field. Although it seems unlikely, these fish have a number of genetic similarities to humans, including major organs. It is mentioned that the arrangement of skin pigment cells begins during the embryonic stage. According to the article, pattern formation is a key feature to organ development which means understanding pigment pattern information, like that of the zebrafish, can give us information on diseases that are caused by the disruption of these cell arrangements. The model is used to study pigment patterning systems, and the pigmentation in zebrafish is an emergent phenomenon which means that the cells act according to their own rules. This was studied by Dr. Kit Yates to determine how these individual pigment cells produced striped patterns in zebrafish without a centralized control system. Robert Kelse, a co-author on the study, explains that it was important to understand this process because it would provide us with deeper insight as to the choreography of cells in the embryo in other organisms as well. The stripes in zebrafish are formed from chromatophores, which are pigment containing cells, and mutations that occur as these cells shift around is what results in alternative markings, such as leopard skin. The scientist, Jennifer Owen, who is responsible for the creation of the mathematical model believes that because of the model's complexity it can help predict other developmental defects and predict cell to cell interactions. It is extremely intriguing that the pattern and the small fish can tell us so much about the general understanding of embryonic development. With this discovery, I can only believe that there is similar research to come with other patterns that can possibly give us a better understanding of mutants and diseases in the vital organs within mammals. In the future it may be possible that with further advancement on the research with zebrafish and other patterned animals that cures or medical advancements can be developed to help these diseases and mutations. Staying on the animal studies, the next article, “Fish eggs can hatch after being eaten and pooped out by ducks,” by Carolyn Wilke definitely caught my eye the most. The article talks about how fish eggs, as delicate as they may be, are able to survive through a duck’s digestive tract and exit through its excrement, contributing to the spread of invasive species. Even though in Orsolya Vincze’s study where birds were fed hundreds of fish eggs within a lab only 0.2 percent of the eggs remained intact after making it through the bird’s guts, it's still extremely surprising they survived at all. It took from one to four hours from consumption to poop out the eggs and especially for migratory ducks, that means these eggs can be spread far from their original “habitat”. This poses so many questions in my head as to how this is even possible. The duck would have to not puncture said egg as it consumes its food and then the egg would have to make it through the entire digestive tract completely unscathed and hatch out of the bird’s excretion. This process was possible within a lab, but it's still unsure if this process would even be possible in the wild. If so, it would explain certain invasive species. If the birds are able to do this in the wild on their own, is it possible that an egg can hatch while it is still inside leading to a live birth as the bird excretes? From the articles I read today, it is clear to me that even with all the research we have on animals, even common species, there is always more to wildlife. I can only imagine how much more there is left for us to discover that can lead to so many medical or scientific advancements to better our society as a whole.
In the article "Fish eggs can hatch after being eaten and pooped out by ducks" by Carolyn Wilke. This article indulges on the topic of fish eggs being eaten, and then exit through the rear end of a duck, which allows for possible invasive species to locate in a different area. It is hypothesized that the reason fish are found so far out in different bodies of water, is because of ducks unknowingly transporting fish eggs do isolated parts of earths water bodies. Many scientists do not believe that this could be possible, but a study conducted by Vincent and her colleagues found that about 18 in 18,000 eggs were intact after defection. Most of the eggs took about an hour to pass, with an outlier taking 4 hours to pass. In this amount of time, the duck can travel a reasonable amount of distance. It is noted the even though the survivor to death ratio is low, these numbers can add up depending on how many ducks consume fish eggs, as well as the amount they consume. Overall i found this article to spark a rather interesting conversation, in which a good amount of research can solve.Not only do i like the article because of the title, but also because of the valuable knowledge it has enlightened me with in my weekly readings.
"Fish eggs can hatch after being eaten and pooped out by ducks" was an unusual, interesting article. It reports on a study conducted by scientists where thousands of eggs of two invasive fish species were fed to ducks and their fecal matter was subsequently examined. While only a small percent did survive after passing through the duck, this percentage still accounts for a large number of fish eggs surviving since fish lay thousands upon thousands of eggs. Since this was only an experiment, it is still unclear if this realistically occurs in nature. However, it does suggest that fish eggs are much sturdier than their soft exteriors say. The second article I read was "How the zebrafish got its stripes." It has been known that zebrafish are a good model for studying human diseases since they share many of our major organs. Analyzing their beautiful skin pigmentation patterns may help develop medicines later on, for pattern formation is a feature of organ development. The University Bath has developed a mathematical model designed to explain how a zebrafish develops its intricate pattern of stripes. By understanding how individual pigment cells coordinate to form clear stripes, we can better understand the coordination of cells in embryos. Chromatophores are the pigment-containing cells in zebrafish, and they shift around as the zebrafish grow until they form the stripes. The model has been able to successfully predict pattern developments in wild zebrafish. It has also been able to predict mutated patterns based on how cells interact with each other, proving the sophistication of its design.
Imagine being a fish egg, getting eaten by a duck, and surviving. Pretty weird, right? That’s how I felt when I read this weeks article “Fish Eggs Can Hatch After Being Eaten and Pooped Out By Ducks” by Carolyn Wilke. Have you ever came across an isolated body of water (a lake) and seen it densely populated with fish? One theory suggests that fish eggs can still hatch after being digested by the duck. In one study, thousands of fish eggs were fed to mallard ducks. 0.2% survived. It’s shocking to learn that eggs can remain intact after being bombarded by the digestive fluids of the duck. However, this may also be a point of error in nature. A minuscule 0.2% can also signify that the duck simple missed the eggs, which allowed them “safe passage” through the excretory system. Most viable eggs were pooped out within the hour, while one took a 4 hour journey in a not-so-pleasant spot.
This week I found the article “A New Theory of Dreaming,” by Neuroskeptic very interesting. As mentioned in the article, the function of dreams has been greatly discussed over the years. David M. Eagleman and Don A. Vaughn proposed a new theory regarding dreams in which they claim that the purpose of dreams is to ensure that the visual cortex is stimulated during sleep. This is because if the visual system were deprived of input all night, then the function could degrade. It is known that the visual cortex could respond to non-visual signals if it does not have visual input. This is proven in blind people's brains in which their occipital lobe strongly responds to touch because their visual cortex is under-utilized. This is known as neuroplasticity in which underutilized brain areas are rewired. According to Eagleman and Vaughn, neuroplasty could be negative in terms of the visual system. Because it is not used at night, our visual cortex could be dominated by our other senses. This is why dreams are used to keep our visual system working and active. Neuroskeptic does not buy this theory because although dreams stimulate the visual system through REM sleep, they are not convinced that it is the main purpose. Neuroskeptic claims that the theory would only make sense if neuroplasty happened very quickly. Although Eagleman and Vaughn talked about evidence regarding rapid neuroplasty, there is no visual evidence. As a result, Neuroskeptic believes that the theory needs to be further tested with a group of human volunteers and an fMRI scan. Half would wear a blindfold while the other half would have REM sleep disrupted at night. While the theory proposed by Eagleman and Vaughn is fascinating, I agree with Neuroskeptic in the sense that there are a few holes within the theory. It needs to be further tested and more visual evidence needs to be found in order for the theory to be proven.
I learned a lot about the zebrafish after reading the article, “How the zebrafish got its stripes.” I found it extremely interesting that the zebrafish can be useful when studying human disease because they seem to have nothing in common with the human body (at least externally). As it turns out, the zebrafish has a similar genetic blueprint, as well as similar organs, to the human body. The fish appears to have stripes because the pigment cells in its skin organize themselves collectively to form a pattern, which is an emergent phenomenon. It is important to pay attention to the stripes on a zebrafish because they represent a developmental process. If scientists are able to comprehend the formation of the fish’s pigment cells, then it will allow them to understand other parallel developmental processes of embryos.
The article, “Fish eggs can hatch after being eaten and pooped out by ducks” was also a very interesting read. When the ducks eat the fish eggs, some of them are able to survive the stomach acids and escape through the duck’s excrement. This is actually beneficial to the environment because it helps to disperse invasive species into different areas. Although a very small number of the fish eggs are able to survive being eaten by a duck, they are still spread to different areas and hatched (especially because ducks are migratory birds).
The most unexpected revelations can come about through experimentation. It’s a known fact for ages that species travel and pop up in unexpected places. Many scientists have wondered- how? How is it possible for invasive species to go from their home to a whole new continent. Scientists believe they have found a way that fish travel- through the gut of ducks. In “Fish eggs can hatch after being eaten and pooped out by ducks” by Carolyn Wilke, the article discusses how fish eggs can be found viable in mallard duck excrement. Wilke writes about research done by Orsolya Vincze, an evolutionary biologist. Vince and his team fed eight mallard ducks thousands of eggs from two carp species. The data revealed that about 0.2 percent of ingested eggs survived. In the surviving eggs, some contained wriggling embryos and a few eggs hatched. However, scientists are still unsure whether eggs can survive in this way in the wild. Although the number of surviving eggs is low, many migratory birds could travel spreading fish eggs to isolated bodies of water. Even though the article’s headline was bizarre, interesting results can explain age old questions.
The concept of dreaming has always interested me, even as a child. It is fascinating to me as to how the human body is capable of creating these scenarios and events that are figments of our imagination but feel as though they are reality, not to mention why dreams occur in the first place. Recently, David M. Eagleman and Don A. Vaughn have proposed a theory called “The Defensive Activation theory: Dreaming as a mechanism to prevent takeover of the visual cortex”. The theory is yet to be published and is currently shared to the public as a pre-print. This theory is further explained and discussed in the article, “A New Theory of Dreaming” by Neuroskeptic. Eagleman and Vaughn’s theory essentially states that dreaming protects our visual cortex by stimulating it in our sleep. This is because it is possible that the visual cortex, the region of the brain that receives, integrates, and processes visual information relayed from the retinas, may deteriorate if it is not used throughout the course of the night. It is possible that the visual cortex can “rewire” itself to also respond to non-visual signals if it is bereft of visual signals. The act of rewiring areas that are not being used as much as they should is known as neuroplasticity. Neuroplasticity in regards to the visual system can be detrimental due to the fact that our sight is used less often than any of our other senses. Anytime that we are in an area that is dark or it is nighttime, we are not able to use our sight fully. Allegedly, our visual cortex would be vulnerable to an attack of sorts conducted by the other senses and, according to the theory, dreams help protect the visual system from this by keeping it stimulated throughout the course of the night. The theory, however, does potentially have some faults, the biggest being the speed of the repurposing of the visual cortex. In order for dreams to have the need to protect the visual system, the repurposing or harmful neuroplasticity of the visual cortex must happen over the span of a few hours; otherwise there is essentially no need for dreams to be a “protector”. To support their theory, Eagleman and Vaughn stated that primates with babies that develop and mature quicker tend to have more REM whereas humans tend to have less REM. They stated that the faster development of a species means that there is slower neuroplasticity, basically meaning that there is not that great of a need to protect the visual cortex. A way to test their hypothesis is to have a group of volunteers who get a baseline fMRI scan to determine how well their visual cortex responds to visual stimuli. Then, throughout the course of a full day, half of the volunteers will have a blindfold on and half of them will have their REM sleep disrupted. After the 24 hours, at which point the volunteers will receive a second fMRI, the volunteers that were blindfolded will have had a less visually selective cortex if their theory is indeed correct.
The first article I read this week was “How the Zebrafish Got its Stripes.” This article begins by mentioning the deep rooted fascination many scientists share in regards to animal pigmentation and its causation. Researches at the University of Bath have recently made progress towards an explanation for animal patterns; they devised a mathematical model that explains how the zebrafish got its stripes. The stripes on a zebrafish are caused by an emergent phenomenon. There are different types of emergent phenomena but in the case of the zebrafish, its cells are able to act on their own accord—they can “self organize”—and arrange themselves in prominent patterns at large scales. Though the explanation of how the zebrafish got its stripes may seem trivial and insignificant, this newly acquired knowledge may be useful for further understanding other animal patterns. I was drawn to another article by the promising headline on our class page and I was not disappointed. The second article I read this week was “Fish Eggs Can Hatch After Being Eaten and Pooped Out by Ducks.” I found this article very interesting because it is about something that I didn’t even know was possible, let alone actually occurred. Apparently, water birds that ingest fish eggs may spread said eggs dozens or even hundreds of kilometers apart. Some of the eggs that have been ingested stay intact once excreted and hatch. Though the survival rate of these eggs remains very low, those that do hatch may add up and the water birds that “transported” them could potentially be responsible for spreading the fish population.
For this week's assignment I read all three interesting articles assigned. The first article was called “How the zebrafish got its stripes”, constructed by a research team at the University of Bath. This team of scientists has been able to construct a mathematical model which explained how the zebrafish developed its stripes. While on the face of it, it may seem insignificant, zebrafish are extremely important to studying human diseases due to their similar genetic and physical characteristics to us, and the formation of patterns is essential to organ development. Therefore, studying pattern formation in zebrafish will allow us to understand diseases caused by the incorrect pattern formation in our organs. Patterns like the ones that form on zebrafish are examples of an emergent phenomenon where cells or individuals can self organise to form a pattern. Understanding the embryonic development that leads to these types of patterns will give more insight on the formation or structure of embryos in their entirety. Specifically to zebrafish, the stripes form from pigment cells called chromatophores which moved around to create their patterns. Mutations would result in splotchy leopard like patterns rather than the linear shape most commonly seen. The model made to determine the pattern formation result has proved successful in both wild type and mutated zebrafish. The next article I read was entitled, “A New Theory of Dreaming” by user Neuroskeptic. This article is almost a personal review on the research paper and theory proposed by David M. Eagleman and Don A. Vaughn, called The Defensive Activation theory: Dreaming as a mechanism to prevent takeover of the visual cortex. To summarise the paper, dreams stimulate the visual cortex during sleep as a mechanism to prevent the degradation of visual cortex function. The writer is not sold on this paper saying that while everything they wrote is scientifically true, he’s not sure it is the prime reason for dreaming. The paper discusses how the rewiring of specific areas in the brain, called neuroplasticity, can occur if dreams don’t occur during sleep, however they do not mention how this could be harmful. The paper lacks sufficient testing however it does seem to have some truth surrounding it, however like the author of the article I’m not sold on this due to that lack of evidence. Finally, the last article I read was called, “Fish Eggs can hatch after being eaten and pooped out by ducks.” This wasn’t as shocking as it was kind of hilarious. After being consumed by a duck, not all of the small fish eggs are eaten. About 0.2 percent of ingested eggs, 18 of 8,000, were intact after defecation in a lab experiment. While the numbers are low, its still plausible for duck feces to spread populations of fish, and i stil can’t believe I managed to make poop jokes uninteresting. This was a much needed break in the consistent development of COVID-19 related news, and provided great insight on the scientific world.
This week the article "How the Zebrafish Got Its Stripes" by the University BATH, discusses exactly what the title states. Skin pigment cells develop during the early embryonic stages in the animal kingdom. Zebrafish are freshwater minnows and although look far from relative to mammals, their genetic makeup is quite similar to us. Pattern formation is an important feature of organ development, and understanding this allows us to learn how diseases are caused by cell disruption in organs. The pigmentation in zebrafish is an example of a phenomenon where cells act on their own rules and organize to form a pattern locally. Dr. Kit Yates states, "Our modeling highlights the local rules that these cells use to interact with each other in order to generate these patterns robustly." Professor Robert Kelsh explains that its important to find a mathematical model explaining the stripes bc it is an example of the developmental process. Being able to understand the pattern development in fish embryos, allows us to gain a deeper understanding into the structure of cells in embryos. The stripes of a zebrafish are formed by pigment cells, chromatophores. There are 3 types of chromatophores, shifting around an animal's surfaces as they interact with one another. Sometimes mutations can occur, which can change how the cells interact during developmental stages in an embryo. The University or BATH developed a mathematical model inclusive of all three cell types and interactions. This turned out to be successful, allowing scientists to predict the pattern development of wild and mutant fish. Jennifer Owen explains that its important to understand pattern development to be able to predict development mutations that are lesser understood. This allows scientists to be able to predict and prevent as soon as possible w the knowledge of early embryonic development.
The article, “How the Zebrafish got its stripes” not only explained how the Zebrafish got its stripes but also the similarities between humans and the fish. For example, Zebrafish have similar major organs as well as genetic similarities which make them helpful when studying human disease. The Zebrafish got their stripes from self-organizing cells that form the patterns. Chromatophores, pigment containing cells, are the cells that self organize to create the patterns. A new mathematical model has allowed scientists to predict patterns through local rules they have discovered. The article, “A New Theory of Dreaming,” talks about a theory two scientists developed to try to explain why dreams occur. This theory is based on the idea that dreams occur to make sure people’s visual cortex doesn’t degrade. The reasoning behind this theory is that if dreams don’t occur then the neuroplasticity of other senses will take over the visual system. Although interesting this theory hasn’t been proven, experiments are being developed to determine if the theory is true or not. The last article, “Fish eggs can hatch after being eaten and pooped out by ducks,” talks about a discovery that could change sea life. This article presents a new finding that some fish eggs can be pooped out perfectly fine after being eaten by a duck. This could mean that the duck could transfer the fish to other places where those types of fish weren’t seen. Although the ducks get rid of the fish eggs in about an hour ducks can travel to other locations to discard the fish.
I read the article, “How the Zebrafish got its stripes”, and this article was talking about the different animal patterns that are present in nature. Scientists at University Bath made a mathematical model to explain how the zebrafish gets its stripes. This model is very important to understanding pigment patterning systems, and similarities between other species. Zebrafish are a type of freshwater minnow and they are used for studying diseases between humans because they have a lot of genetic similarities with humans, as well as physical characteristics such as organs. The stripes of zebrafish are made of cells called chromatophores, as the organism continues to develop they will shift and interact to self organize into the stripes pattern. Many researchers and mathematicians have been trying to find an explanation for how the zebra fish’s stripes form for many years, but this model has made it possible to see how the patterns will form in wild fish and mutant fish.
The purpose of dreams are still unknown in the scientific community. A recent theory was made to explain why we dream. The theory stated that the visual cortex would degrade if it’s not constantly stimulated. Why this logic does make sense, there are some holes in the theory. In the dark, there is no visual stimulation, so the brain requires the cortex to react to other senses such as touch. However, it is interesting to believe that dreams are meant to protect the brain. ( this is a little off topic ) but let’s say dreams ARE made to protect the brain and functions, then why do people get nightmares so terrifying that they are traumatized? Anjana
This weeks article was titled “How the Zebrafish got its stripes.” The article starts off explaining all animal patterns. It says how the stripes spots and rosettes seen in the wild or a source of endless fascination and how researchers have developed a mathematical model to explain how one important species, the Zebrafish, develops its stripes. The article then goes on to state how in the animal kingdom the arrangement of skin pigment cells starts during the embryonic stage of development making pattern formation an area of keen interest not only for scientists but development biologist and mathematicians as well. The article continues on how a zebrafish may also be able to provide fundamental insights into the complex process that underpin biology and how in time studying their appearance may be relevant to medicine since pattern development is important to organ development. As we continue into the article a new math medical model devised in Bath is shown to us. This will be for further exploration into pigment pattering systems. The article finally comes to conclusion by talking about two final points. Scientists know a lot about the biological interactions needed for the south organization of a zebrafish is pigment cells but there are has been some uncertainty over whether these interactions offer a comprehensive explanation for how these patterns form. The second point being how mathematicians have been trying to explain how zebrafish stripes for for many years that have never been able to know why because they’ve never been able to account for the broad range of fish mutant patterns, but now thanks to Jennifer Own we can now help to predict the developmental defects of some less understood mutants. Some examples of this are the cell cell interactions that are defective in mutants such as leopard which displays spots. All in all this was a very interesting read. I really enjoyed reading the article on “How the Zebrafish got its stripes” and how this can lead to the understanding of less understood mutations.
The article I found most interesting was "How the zebrafish got its stripes." The article discusses how animal patterns are a source of endless fascination. Scientists and researchers have just discovered how zebrafish got its stripes. Before zebrafish in the animal kingdom, skin pigment cells start during the embryonic stage of development, which patterns begin to form. The reason why researchers study zebrafish is that it may be relevant to medicine. I've learned that pattern formation might give us insights into diseases caused by disruption among organs. An emergent phenomenon is when one in which individuals (cells in this case), all acting according to their own local rules, can self-organize to form an ordered pattern at a scale much more massive than one might expect. An example of this would be synchronized swimming among a school of fish and pigmentation in zebrafish. It's essential to find the correct mathematical model because patterns are exciting and beautiful in their own right and an example of critical developmental processes. The stripes of an adult zebrafish emerge from pigment-containing cells called chromatophores. As the animal develops, these pigment cells shift around on the animal's surface, interacting with one other and self-organizing into the stripy pattern for which the fish are named. In conclusion, mathematicians have been trying to explain how zebrafish stripes form for many years; however, many previous attempts have been unable to determine from the broad range of observed fish mutant patterns.
This week I read "A New Theory About Dreaming". This immediately caught my attention because I find psychology and neurology very interesting. I am amazed every time I learn something about the thousands of functions the brain is doing while we are asleep. For example, how the body enters a state of paralysis while dreaming or theories about how everything and everyone we dream of is something we have seen in real life because that's just how much sensory processing our brain does even if we can't consciously recall it. However, I would not have guess that dreams were a form of defense against degrading. I agree with the author that this could be a function of dreaming, but it may not be the main function. Since our brain is still very active during sleep, it seems hard to believe that it could degrade so quickly. It was interesting to find out that in theory, our visual cortex can be taken over by other sense- I didn't know that was possible. I learned about specific details about neuroplasticity, such as that it can not occur so quickly in a few hours. This makes me wonder what factors contribute to neuroplasticity and how long would it usually take? How much does it have to do with aging, the environment, genetics or simply the individual? The correlation on the graphs essentially meant that faster development means slower neuroplasticity so less need to protect the visual cortex. However, I think there are too many other factors that could've affected the primate's maturity. It could be very helpful to do a more specific study on humans like the author suggested towards the end. This would help make this claim more supported with hard evidence.
With the world constantly growing in discoveries, new research is able to answer several questions that arose from the study of skin pigment cells and their interactions. In the article, “How the Zebrafish got its stripes,” published after a study held by a team in the University of Bath, I learned that there is a link between pattern formation and organ development for feature-like purposes. Due to this link, teams involved in medical research about diseases are better able to understand a disruption between cell arrangements within organs (ex: heart) that result in a disease. The beauty of simple to complex processes in science opens the mind to the great possibilities yet to learn. For instance, Zebrafish pigmentation is a type of emergent phenomenon in which cells, in simple definition, are able to self-direct themselves into an organized fashion to produce a specific pattern. However, like ever new discovery, the research won’t end until every possible question can be answered in relation to how Zebrafish obtain their stripes and its benefit to the scientific community. The second article I read, “Fish eggs can hatch after being eaten and pooped out by ducks,” I figured that death may not be so inevitable in certain scenarios. With the spread of fish who survive from the gut of ducks, there will most certainly be a change in the allele frequency in the community it is forced to settle in, however, whether their addition in the community is healthy for their population and environment is dependent on their selective adaptations. Hundreds of years later, evolution may even allow fish to adapt in environments that would be a shocker to those who lived in the past, who knows? The great factor about science is that it can get a little funky here and there, which makes it all much better to get involved in.
This week for AP Bio, I read “how the zebrafish got their stripes”. researchers from the University Bath developed a mathematical program to predict natural phenomena such as stripes or spots on an animal. Because pattern development is a major part of organ development, studying these natural phenomena could help us learn more about diseases and other disorders. These new programs can predict patterns in pigmentation. The zebrafish have three different chromatophores that self-organize and result in the stripe pattern of the zebrafish. Different mutations could even result in a labyrinth or maze looking pattern. Professor Robert Kelsh summed it up by saying its important to learn about these patterns “Partly, because pigment patterns are interesting and beautiful in their own right. But also because these stripes are an example of a key developmental process. If we can understand what's going on in the pattern development of a fish embryo, we may be able to gain deeper insight into the complex choreography of cells within embryos more generally."
In my opinion, the most intriguing of the three articles was, "Fish eggs can hatch after being eaten and pooped out by ducks." The article gives insight into other ways, besides humanity, invasive species get into the environment. Due to the strange properties of the eggs, it could mean that these species of fish have evolved so their eggs may survive their predators' digestive systems. It brings into question if our current ecosystems are made up of formerly invasive species that became a normality in these environments. Species to take into consideration if they were formerly invasive are those that have many offspring in one reproductive conception. Similar to the fish, these children would mostly die, however, the few that survive would invade their new environment. The article's questions are what drew me to it as we may have to rethink our whole ecological movement against invasive species and come up with new ways to handle invasive species in the future.
In the first article I read this week, “How Zebrafish got its Stripes,” published by the University of Bath explained animal patterns seen in nature (stripes and spots). The university developed a mathematical model to understand how zebrafish obtain their stripes. The fishes share similar genetics and physical characteristics to mammals, as a result they are relevant to medicine. Studying their appearance and pigment pattern formation can inform us about diseases about organ arrangements. An example of the development process are the stripes. If we understand the pattern development, we can learn the intricate choreography of cells in embryos. The Bath team has created a model of the three cell types and how they interact to predict future patterns. The scientist, Jennifer Owen, is accountable for the model which can help predict the defects to mutants that weren't understood before. The second article, “A New Theory of Dreaming,” reviewed by Neuroskeptic was a review on David M. Eagleman and Don A. Vaughn’s new theory about dreaming. They believe the brain’s visual cortex is simulated during the 6-10 hours of sleep. Without dreams, the function can negatively be affected. However, the author is skeptical of the theory and is convinced the sole purpose of a dream is not for the stimulation. Neuroskeptic explains the theory would make more sense if the neuroplasticity had a harmful effect over a period of time, however, there was no evidence to support that. They compared the amount of REM sleep and the time of development among primate babies. The faster the babies’ development, the slower the neuroplasticity, which leads to less need to protect the visual cortex. The reviewer believes to test the theory, they would need a group of humans to take an fMRI scan (to scale the visual cortex). After 24 hours half of the group would blindfold themselves to stimulate visual deprivation. Half of the group would get REM sleep disrupted to enhance the effect. In the end, they would have to take another fMRI scan to see if they had a less visually selective visual cortex. All in all, I was fascinated with the theory and I enjoyed the contrasting review given by Neuroskeptic, however, in order to make a definitive judgment on the theory more evidence and tests would need to take place.
In the article "A New Theory of Dreaming" by Neuroskeptic, it talks about how and why we dream, as well as what could it represent. To this day neurologists still don't have an accepted answer to this age old question. A new theory has been proposed, and dreaming is just a mechanism that the mind made up to keep the visual cortex in top shape. if it is deprived of visual input (seeing things) then it may respond to non-visual signals. In general neuroplasticity is an amazing feature to improve the brain, however when it comes to the visual cortex it becomes a threat to our vision. This is a good theory, however it simply doesn't make sense. dreams do still affect the visual cortex, but that isn't the purpose of them, their theory only makes sense if neuroplasticity happened at an extremely fast rate. Although it can occur within a few hours, it has not been proven that it is harmful. This is a very interesting topic as dreams are still one of the unsolved mysteries in the science community. This specific theory can be tested easily. take an fMRI scan, from multiple volunteers to see how selective their visual cortex is. Then have half of the volunteers wear a blindfold to produce visual deprivation, and have the other half, have REM sleep, both for 24 hours. and at the end they both get an fMRI scan to determine how this has effected their brain. Overall this is a very interesting topic and one could dive very deep into how vast and unpredictable the human brain is.
This week I chose to read the article, “A New Theory of Dreaming” written by Neuroskeptic and was quite fascinated by it. The author of the article writes about David M. Eagleman and Don A. Vaughn’s theory on why we dream. The scientists hypothesize that the reason we dream is to ensure that we stimulate our visual cortex while we are sleeping to prevent it from degrading over time. Scientists know that the visual cortex, located in the brain’s occipital lobe, can respond to non-visual signals if there is no visual input. This is a phenomenon that occurs due to neuroplasticity, the trait that allows the brain to repurpose un-utilized or under-utilized areas. Neuroplasticity has its benefits, however it can be detrimental because not all your senses are active all the time, particularly vision. Eagleman and Vaughn hypothesize that in order to prevent the visual cortex from being “taken” over by other senses every night, we dream. If we didn’t dream, as Eagleman and Vaughn claim, the integrity of our visual system would degrade over time as a result of a period of dormancy every night. Although, as pointed out by the author, there are a few flaws with this theory. The author points out that for Eagleman and Vaughn’s theory to make sense, neuroplasticity has to occur really quickly. For the visual cortex to need defending, the brain would have to harmfully repurpose the cortex in a matter of a few hours, which seems unfeasible. Eagleman and Vaughn base their theory on the fact that primates that develop faster have a slower neuroplasticity; this means that humans, the slowest developing primates, have a faster neuroplasticity. However, there is no sufficient evidence that proves said point and an experiment that tests this theory has not been carried out. I personally think that this theory is flawed due to the nature of our dreams. Our dreams generally revolve around our desires, subconscious feelings, abstract thoughts, etc. If our dreams were truly about maintaining our visual cortex, why would they not be realistic, revolving around our everyday day life instead. The reason we dream of our subconscious desires and thoughts is likely a method for our brain to cope with pressures of our everyday life and allow us to reconcile with these feelings or provide us pleasure by fulfilling our desires. Our brain likely does this to maintain our mental health by providing us with scenarios of our subconscious desires and thoughts taking place to prevent these feelings from eating us up from the inside. Ultimately, I disagree with Eagleman and Vaughn’s “Defensive-Activation theory” due to the several flaws within the theory.
“A New Theory of Dreaming” by Neuroskeptic proposes a theory in response to the renowned question: why do we dream ? Scientists Eagleman and Vaughn theorize dreams ensure that our brain’s visual cortex is stimulated during its sleep. According to the theory when our visual systems are deprived of input the visual cortex located in the brain's occipital lobe degrades. Our visual cortex when deprived of visual input can start to respond to non-visual signals. For example, in blind people have an intense reaction to touch due to their occipital lobe being under-utilzed. Furthermore, the occipital lobe starts giving strong responses to touch instead of visual information due to the elongated period of time without any visual input. This rewiring in under-utilized areas in the brain is a form of neuroplasticity. Overall, the theory’s main point is that dreams are used for our brains to defend the integrity of our visual system to keep it active. Unfortunately, Eagleman and Vaughn do not provide direct evidence of dreams being used as defense. They openly admitted to the lack of factual information by saying "The present hypothesis could be tested more thoroughly with direct measures of cortical plasticity". It should also be noted that the scientists show a correlation between the amount of REM sleep and the pace of development among primate species. With this information they are trying to convey that faster development means slower neuroplasticity which in turn means there is less of a reason to protect the visual cortex. Lastly, I wanted to address how interesting this passage and hope soon enough the hypothesis proposed in the article can be properly tested to either prove or disprove the new theory.
This week I read “How the zebrafish got its stripes”. This article talked about the skin pigmentation cells in a zebrafish can be mutated to create different patterns on the fish. The zebrafish are very helpful for human research because their genetics and major organs are very similar to those of humans. By understanding the arrangement of pigment cells on zebrafish, we may be able to understand diseases caused by cell arrangement. These different pigment cells act without any central control but they still manage to create the stripe pattern on the fish according to Dr. Kit Yates. The stripes signify a key developmental process that can help humans further understand how these cells arrange themselves while in the embryos. This article interested me because it shows how just a small mutation can cause such a drastic change in appearance. Now that I know that zebrafish are similar to humans in their genetic makeup, it will interesting to see if these studies can be applied to humans on a widespread basis. I wonder what kind of factors impact the likeliness of a mutation or if they are just random.
After reading “How the zebra fish got its stripes”, I now know so much more about the process of how cells affect the pattern on animals. This research can help scientists studying medicine, find more information about certain diseases. Zebrafish might not in common with mammals but they have many genetic similarities to humans. Stripes on a zebra fish are called chromatophores which are pigment containing cells. There are three different types of chromatophore in the fish. The cells move around on the animal's surface and interact with one other and organize into their stripy pattern. Mutations can appear which can change how cells interact with each other and cause a different pattern on the fish. Mathematicians have been trying to figure out how zebrafish stripes form for many years. Scientist Jennifer Owen said that “it can help to predict the developmental defects of some less understood mutants.” Overall, scientists are discovering more information about how cells form the pattern on zebrafish which can help relate to cells in humans.
In the article, “How the zebrafish got its stripes,” I got a deeper understanding of the pigmentation of zebrafish. There were researchers at the University Bath who created a mathematical model to explain the method that the zebrafish uses to develop stripes. Most animals develop their skin pigments in the embryonic stage. Zebrafish are also popular because their genetic makeup is greatly similar to that of humans. Their biology allows for a better understanding of organ development and a better understanding of diseases caused by malfunctions in cell development. The zebrafish’s pigment cells work individually from one another and organize themselves into patterns. Creating an accurate model of their arrangement methods allows for a better understanding of how cells coordinate with each other when developing. Zebrafish pigment cells are called chromatophores and there are three types of them, which can interact with each other to produce the striped patterns as well as mutate to organize different patterns. University Bath was able to produce an accurate model of these three types of pigment cells to predict the patterns on wild and mutant zebrafish. In the article, “Fish eggs can hatch after being eaten and pooped out by ducks,” I learned that some fish eggs have the possibility of surviving being eaten and then excreted. It was at first believed that eggs couldn’t survive being ingested by birds but after some lab tests, it was proven otherwise. A lab experimented on mallard ducks by feeding them invasive carp eggs, which was later excreted by the bird. Some of the eggs had survived being ingested, which gave a possible explanation to how species of fish could’ve been spread. Even though only a small percent of the eggs survived, the sheer amount of birds excreting them during their migratory travel could allow for a greater spread in invasive fish species.
Today I read, "Fish eggs can hatch after being eaten and pooped out by ducks." This article at first drew out my curiosity and after reading it, it was very informative. Apparently the discovery of fish eggs are able to survive after being ripped apart and eaten by ducks. When ducks poop, the eggs are still in the excrement and can later survive when it underwater. Very minimal fish are actually killed in this process.
I found the article “A New Theory of Dreaming” to be interesting. It started off by asking a question of why do we dream. David M. Eagleman and Don A. Vaughn came up with a theory that we have dreams to make sure our brains visual cortex is still stimulating while we are sleeping. The one thing they point out in their theory is that when we’re in the dark we can’t see so in theory our visual cortex takes over our other senses. The article also included that if someone has a slower neuroplasticity it means the visual cortex needs to be less protected. The article really helped me clarify as to why we have dreams and when we don't.
I read the article “Fish Eggs can hatch after been eaten and pooped out by ducks” by Carolyn Wilke. I found this article quite interesting and was drawn to it by the intriguing title. After reading this article I was surprised, as it had me thinking about all of the more unconventional ways that an invasive species could be introduced to an ecosystem. Although the amount of eggs that survived the duck’s gut was low, as stated in the article, these numbers could slowly start to add up and could create a real problem by introducing new species‘ to new ecosystems.
Within the article “How the Zebrafish got its stripes” the University Bath has started employing a mathematical model to show how Zebrafish get their striped design. This captivating handle is being studied by both formative researchers and mathematicians to make this scientific demonstrate. Researchers have found that the arrangement of this design happens amid the embryonic organize through skin color cells. They have found that the Zebrafish have a parcel of physical characteristics that are comparative to warm blooded creatures, particularly comparable organs. Due to the comparative organ improvement researchers are looking into the design arrangements in connection to medicine. By knowing how the pattern shapes in Zebrafish, researchers can have distant better;a much better;a higher;a stronger;an improved">an improved understanding of infections within the organs that are caused by the disturbed cell courses of action. By and large the College Shower is interested by the marvel in which person cells of the Zebrafish associated and organize the striped design without a central control
In the article, "How the Zebrafish got their stripes" the university of Bath used a mathematical model to represent the Zebrafish design. It was a very interesting article and I learned in how much effort was put into the process of finding fish. Zebrafish have skin color cells. With the knowledge on how zebrafish got their stripes, scientists can now tell how infectious diseases occur in them.
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The article I read this week was “Fish eggs can hatch after being eaten and pooped out by ducks”. I found this interesting not only because of the title of the article but also because scientists and researchers actually thought this topic was an important one to discuss. I found it interesting that even a few fish eggs could survive the stomach acids and the gizzard and that this was an open question for centuries according to Patricia Burkhardt-Holm. I also find it amazing that since fish eggs are soft and the bird feet, feathers, and feces can spread only “hardy plants seeds and invertebrates”, the eggs were still somehow able to make it through the gut. Even though only 0.2% of the eggs were intact, some were able to hatch. This is still an important step to answer the question of how bodies of water are so populated with fish. Birds that migrated could travel many miles before getting rid of the eggs which can transport the species of fish to many places. This will then allow for the population of fish to many areas because one carp can release “hundreds of thousands of eggs at a time”.
Today, I read the article, “How the Zebrafish got its stripes”. The article discussed animal patterns, which are the spots and stripes seen in nature. Researchers at University Bath have made a mathematical model in order to explain how the Zebrafish developed its stripes. Zebrafish, fresh water minnows, are used for studying human disease because they show many genetic similarities with our species. In addition, they also have several similar physical characteristics as us, including organs. The new mathematical model that was made by University Bath is critical to understanding pigment patterning systems, as well as their similarity between different species. The stripes of an adult Zebrafish are made from cells called chromatophores. As the animal grows, the pigment cells shift on the surface of the animal, and interact with one another to then self organize into the “stripes” pattern. Mathematicians have been trying to explain the forming of stripe on zebra fish for several years, however, the model made now has proven to be successful in predicting the development of pattern in both mutant and wild fish. In addition to this article, I also read, “A New Theory of Dreaming” by Neuroskeptic. The article discusses a new theory for why humans dream. Eagleman and Vaughn believe that we dream to make sure that the brain’s visual cortex is kept busy while we sleep. If not, the functions of the visual cortex may worsen over a period of time. However, their theory only makes sense if nueroplastic repurposing happens very quickly. Although, there is no evidence to show that these fast changes can be harmful to us. Both Eagleman and Vaughn’s theory would also predict that people who are vision-deprived would have less selective visual cortex, and so the REM disruption would strengthen this effect. In conclusion, these are the two article that I read today.
“How the zebrafish got its stripes” was a topic of great interest in the University of Bath, that a mathematical model was made to explain it. By studying their pattern formation it can help with the study of organ development and diseases. The mathematical model devised by the university discovered that the pigmentation in zebrafish is an example of an emergent phenomenon. This model can further explore a variety of pigment patterning systems in different species. Dr.Kit Yates, the mathematician who led the study, believes that the model will be able to highlight the rules that pigment cells use to interact with each other in order to generate patterns. Professor Robert Kelsh, co-author of the study, sees that by understanding the pattern development of a fish embryo they will be able to have a deeper insight into the choreography of cells in the embryo in a broader spectrum. The chromatophores, the pigment-containing cells, give the stripes of an adult ‘wild type’ zebrafish. The cells shift around on the animal’s surface and interact with each other and self-organise to make the striped pattern. Jennifer Owen, the scientist who built and runs the model, explains that thanks to the model it can help to predict the cell-cell interactions that are defective in mutants. Prior to having read this, I did not think much about how certain animals have a distinct pattern on their body. After having read this article it is shocking to learn how complex cells work.
“A New Theory of Dreaming” offers a different perspective on why people dream. Eagleman and Vaugh’s theory: “The role of dreams is to ensure that the brain’s visual cortex is stimulated during sleep. Otherwise, if the visual system were deprived of input all night long, the visual cortex’s function might degrade.” The visual cortex, in the brain’s occipital lobe, can respond to non-visual signals if it is deprived of visual input. This is a form of neuroplasticity which is posed as a threat in Eagleman and Vaughn’s theory because it is not active all the time. In other words, dreams are our brain’s way of defending the integrity of our visual system by keeping it active. The author of this article does not buy this theory to be the main purpose of dreams. Eagleman and Vaughn do not hold any direct evidence claiming dreams are a defense mechanism against neuroplasticity and there is also no evidence that rapid neuroplasticity can be harmful. Eagleman and Vaughn show a correlation between the amount of REM sleep and the pace of development among primate species. The author suggests that the hypothesis, “the idea that faster development means slower neuroplasticity, and slower neuroplasticity means less need to protect the visual context from encroachment,” could be tested by conducting a controlled experiment. Overall, I think this theory is quite interesting because I always wondered why I dream at night. However, I wish that this article gave some insight about what our dreams mean and if there is an underlying meaning behind them.
“Fish eggs can hatch after being eaten and pooped out by ducks” by Carolyn Wilke offers an interesting discovery that some fish eggs can exit the duck’s excrement, hence possibly helping to spread those fish to different places. Researchers have known that birds’ feathers, feet, and feces can spread hardy plant seeds and invertebrates but shockingly they never expected their feces to carry fish eggs because of how the journey of the egg includes the gizzards of the bird and an attack of stomach acids. Orsoyla Vincze, an evolutionary biologist at the Centre for Ecological Research in Hungary, and her colleagues led a lab where they fed 8,000 eggs to eight mallard ducks. The results showed that 18 ingested eggs were intact after defecation. After having just read the title of this article, I was so shocked and surprised that birds are an important vehicle for spreading fish. It is so surprising that some fish eggs are able to still survive and hatch after going through a bird!
The article “How the zebrafish got its stripes,” published by the University of Bath focuses on how the mathematical model developed to predict how stripes formed on zebrafish can be used to make scientific and medical advancements. Patterns are believed to have a strong correlation to organ development. This has caused some scientists to believe that by studying pigment pattern formation, they will be able to learn more about diseases that result from the disruption of an organ’s cell arrangements. Using this new information, they are hoping to make advancements in the medicines used to treat those diseases. Scientists hope that the mathematical model developed at Bath can be used to highlight the similarities in pattern development of different species. In zebrafish, pigmentation is an example of an emergent phenomenon, which is where cells function according to their own rules. This phenomenon was studied by Dr. Kit Yates who focused on how the model can reveal how pigment cells can produce specific patterns without coordinated centralized control. He believes that by studying this in zebrafish, discoveries can be made on the development of cells in fish embryos and embryos in general. Jennifer Own, who is credited with the development of the model, believes that due to the model's complexity, many revelations can be made on the development of embryonic cells. It’s crazy to think that huge scientific discoveries can be made based on studying the patterns of small fish. This realization will most likely set the precedent for future studies on the patterns of organisms who share similar organ structures to mammals. If the stripes of small fish can lead to a better understanding of embryonic development, it is very likely that more information is currently hidden in the patterns of other animals. Studying these organisms can give us a better understanding of the diseases that attack the organs of mammals. By analyzing the zebrafish and other similar creatures, perhaps we can come to some conclusions on possible medicines to treat these illnesses.
I read the article “How the Zebrafish got its stripes”. Zebrafish are actually valuable for studying diseases that affect humans. They show many genetic similarities and have similar physical characteristics, including major organs, to humans. Marine biologists believe that studying their appearance may, in time, be relevant to medicine , since their pattern formation is an important general feature of organ development. Professor Robert Kelsh, co author of this study explains, “ If we can understand what’s going on in the pattern development of a fish embryo, we may be able to gain deeper insight into the complex choreography of cells within embryos more generally.” I find it really cool that a simple thing such as a fishes’ stripes can help understand diseases caused by disruption to cell arrangements within organs.
In the article “A New Theory of Dreaming”, Neuroskeptic talks about a new theory proposed by David M.Eagleman and Don A.Vaughn called The Defensive Activation theory:Dreaming as a mechanism to prevent takeover of the visual cortex and how Neuroskeptic doesn’t accept this theory. The theory states that the role of dreams is to ensure the brain’s visual cortex is stimulated during sleep, and if the visual system were deprived of input all night long, the visual cortex’s function could degrade. Pretty much, the visual cortex starts to respond to non-visual signals if it doesn’t receive visual input. This change of function of under-utilized brain areas is known as a form of neuroplasticity. Neuroplasticity is usually considered a good thing, but Eagleman and Vaughn state that for our visual system, neuroplasticity can be very bad because our vision isn’t active at all times. Looking from this viewpoint, dreams are our brain’s way of defending the integrity of the visual system by keeping it active, therefore lowering neuroplasticity. Although Neuroskeptic believes that this is a unique and never talked about idea, he doesn’t believe that it isn’t the main purpose of dreams. Neuroskeptic talks about how this theory can only make sense is neuroplasticity repurposing of the cortex happens very quickly, and although the authors of the theory discuss evidence that rapid neuroplasticity can occur, they do not talk about how these changes are strong enough to harm. He also states how the authors don’t discuss any direct evidence for dreams serving as a defense for the visual cortex. He then continues by talking about the correlation between amounts of REM sleep and the pace of development among primary species, which was shown by the authors to prove that faster development means slower neuroplasticity, and slower neuroplasticity means less need to protect the visual cortex from encroachment. At the end, he discusses an experiment to help prove this theory. I personally believe this theory is very unique and interesting, and I like how people can have different viewpoints for the same theory and how they can back up their statements with a good amount of evidence. Neuroskeptic’s argument against this theory was very informational, and he does manage to prove his point very well. In conclusion, this article is great to read and it was fun to learn about an idea that can answer a question thought about for decades.
I read the article about dreams and it was quite fascinating. The understanding and knowledge of dreams is very limited and still something neuroscientist and psychologists still struggle to understand. There are new theories that come up from time to time but still doesn’t give an answer that everyone believes. This new theory that has emerged although has scientific evidence to prove its accuracy still has many rejected the idea such as the author of this article. The new theory has many holes and questionable statements that proves how little we truly know about dreams. The theory that Eagleman and Vaughn’s have proposed suggests that the brain projects dreams in order to stimulate the visual cortex during sleep so it doesn’t deteriorate. Although this hypothesis seems alright the author does not believe it. He says that dreams might be more complex and have a deeper meaning and purpose. I agree with the author. It is hard for me to believe that the only reasons dreams exist’s is to stimulate a part of the brain that isn’t used while sleeping. I think that dreams mean more and show a lot more than that.
In the article, “Fish eggs can hatch after being eaten and pooped out by ducks,” the topic of water birds being a form of transportation for fish eggs was discussed. A certain food for water birds is fish eggs. Usually, thousands of eggs are ingested by these birds at a time, and only a few of the eggs are able to survive being in the stomach of a water bird. In a study conducted by Orsoyla Vince and her team, they were able to find out that about 0.2 percent of eggs that were ingested were intact. Before the eggs are excreted by water birds, these birds can travel dozens or hundreds of kilometers, which would explain why certain fish are present in isolated water bodies.
The article “A New Theory of Dreaming” by Neuroskeptic informs readers of a new theory regarding the purpose of dreams. The theory, proposed by David Eagleman and Don Vaughn, states that dreams are necessary in order to keep the brain’s visual cortex stimulated. Without dreams, they believe that the visual cortex will become inactive and its function will degrade while sleeping. The function of the visual cortex is to process the visual information received by the eyes. When it is not properly functioning, the visual cortex will begin to process information that is non-visual. An example of this occurring is in blind people, where other senses, especially touch, stimulate the visual cortex in the occipital lobe of the brain. It is interesting that certain parts of the brain can adapt to changes and carry out a different function than intended. However, this form of neuroplasty can actually endanger the functions of the visual cortex. Vision is not active in the dark, so there is a possibility for the visual cortex to be rewired and only respond to other senses. Dreams, however, keep the visual cortex active while sleeping and when the brain is unable to receive visual information from eyesight. This information is explained further in a preprint of the theory proposed by Eagleman and Vaughn. However, Neuroskeptic is not completely convinced by this and points out a few holes in their theory, such as the fact that neuroplasty would have to occur quickly in order for dreams to act as a defensive mechanism. Although there is also not much evidence to back up this claim, it still seems fascinating that dreams could have the purpose to protect certain areas of the brain.
I read the article, “Do dreams exist to protect the brain's visual cortex?” I really enjoyed this article and found the author’s skeptical tone to be interesting. The author highlights a hypothesis posed by David M. Eagleman and Don A. Vaughn. The researchers believe that dreaming is used to protect the visual cortex from takeover. The author is intrigued but not fully convinced by the hypothesis. He agrees that the brain can respond to non-visual signals if it is deprived of visual input for a long period of time, but does not believe that this period of time could be as short as a few hours (the period which we are asleep for). This process is a form of neuroplasticity, and the author thinks that this theory should be further tested to understand the full effects of this process. He proposes a test where volunteers would be given a fMRI scan as a baseline, followed by half the subjects being blindfolded for 24 hours. Then, the subjects would receive another fMRI. If Eagleman and Vaughn are correct, the subjects who were blindfolded would have less visually selective visual cortex. Thus, this article is important in furthering the research of this hypothesis.
When I was younger I have always wondered where dreams come from, or why we have dreams. However, no one really knew the answer to my questions. Recently a new theory has been put forth by Dr. Eagleman and Dr. Vaughn. They claim that the human bodies form dreams in order to protect the visual system. It is known that other senses are heightened when people are deprived of visual inputs. During the night, the visual cortex is weak and can be taken over by other senses. This can be harmful since the ability for the visual cortex to function can be reduced. However, this theory seems to be challenged by the author of the article. The author claims that there is no evidence whether harmful nueroplasticity can occur within a few hours. Both Dr. Eagleman and Dr. Vaughn provide evidence that rapid neuroplasticity can occur, but the harmfulness of it is still unclear. They also discuss the relationship between development and amount of neuroplasticity. They claim that the amount of REM sleep is lower when the rate of development is higher in primates. This means that babies who learn how walk faster and those who mature faster, have less dreams than babies who take a longer time to learn. However, their hypothesis doesn’t have enough evidence as they could have used better methods of testing. The author of the article proposed an experiment with human volunteers. These volunteers would be given an fMRI scan before and after to note the change. Half of the volunteers would wear a blind fold for 24 hours to stimulate visual deprivation and the other half would experience disrupted REM sleep. Using the fMRI scans, experts can determine the affects of the visual cortex on dreams. This experiment must go through multiple trials in order to provide accurate and reliable information. I believe this one of the several reasons that humans have dreams. Although this theory seems slightly far fetched, it could be a breakthrough for all of the questions revolving around the origin of dreams.
The first article I read was “How zebrafish got its stripes” by Vittoria D’Alessio. The article was about the pigment-filled cells (chromatophores) coming together to form patterns on the zebrafish. The way that animals can achieve the patterns we see was under speculation until the University of Bath discovered calculations to justify the zebrafish’ stripes. Once scientists dug deep, they found fascinating information. The formation of skin coloring agent cells for animal occurs throughout the embryonic period of growth. They make patterned structures, a topis of specific importance to scientists like developmental biologists and mathematicians because these studies could help treat many diseases. There are many unseen similarities between zebrafish and humans, like major organs. These similarities could help medicine in the long run. If biologists study these animals and justify why things are, they can make modifications to the cell to prevent problems, if any. An example of this is pattern formation, which is a critical event in organ growth. The chromatophores (pigment-filled cells) act like a flock, or a school of fish; synchronized. They come together to form something larger than themselves. The streaks are a representation of the core stage of growth. Studying these streaks will let us explore the routine of the cell in embryo in common. The cells are moving while the species is growing, so interact with each other to create a certain pattern. As they are interacting with each other, mutations take shape and create other patterns like spots. What is surprising and so fascinating, is that these cells do not work for a centralized factor. I find it astonishing that something as simple as stripes, has such a complex, and concealed background. Numerous small parts, like molecules and cells, have come together to create these stripes on species, but humans still can’t explain it in detail.
The second article. “A New Theory of Dreaming” by Neuroskeptic, is about how the theory David M. Eagleman and Don A. Vaughn’s theory was invalid. Eagleman and Vaughn’s theory of the function of a dream is: “The role of dreams is to ensure that the brain's visual cortex is stimulated during sleep. Otherwise, if the visual system were deprived of input all night long, the visual cortex’ function might degrade.” A type of neuroplasticity is other sensors kicking in when another is unable to. This can be harmful to an already weak sensory tool since it won’t get the exercise it needs. The writer of this article, Neuroskeptic, doesn’t believe that Eagleman and Vaughn’s theory is the main function of dreams. One point that they make is within a few hours, damaging neuroplasticity would have to happen. On the other hand, dangerous neuroplasticity usually occurs in a long time, which doesn’t allow the sensory tools to weaken.
The third article I read was “Fish eggs can hatch after being eaten and pooped out by ducks” by Carolyn Wilke. I found this article especially interesting because it was something unexpected. This article was about how bird-dispersed fish eggs all over different bodies of water. Many biologists didn’t expect fish eggs to survive the digestive system of the bird since fish eggs are soft. The eggs surviving can explain things, like how the different and same types of fish are dispersed throughout one or many bodies of water. When some biologists were testing this, not many eggs survived, but it was still an impressive amount who did survive. Approximately 0.2 percent of eggs were eaten survived, which would be 18 out of 8,000. While the amount of intact eggs is low, their numbers can contribute to making bird feces crucial transportation for fish. Vincze, a biologist at the Centre for Ecological Research in Debrecen, Hungary, says a single fish can produce hundreds of thousands of embryos at a time. And there are large numbers of birds all over the world which can prey on those eggs alone.
The article that I read was “How zebra fish got its stripes”. Researchers at the University Bath have studied and have developed a model to explain how the zebrafish develops its strips. These species of fish are very important for studying the human disease. They have many genetic similarities to our species. Furthermore, we have many similar physical characteristics. The researchers believe studying their appearance may be relevant to to medicine. The reason is that the pattern formation is an important feature of organ development. Furthermore, the researchers want to better understand the pigment pattern formation, so they can give us insights into diseases caused by disruption to cell arrangements within organs. The new model created by Bath further explains the pigment patterning systems, and shows the zebrafish similarity to other different species. The stripes of the zebrafish is an example of an emergent phenomenon. Emergent phenomenon is when individual cells all act to their own local rules to form an ordered pattern. Dr. kit Yates from Bath explains how the model shows the local rules that these cells use to interrelate with each other to create these patterns.
I chose the article "A New Theory of Dreaming" for this week's post. This article was interesting to me since it addressed the mystery of dreams in the human species. The newest theory proposed by David M. Eagleman and Don A. Vaughn claimed that is dreaming is used for avoiding the visual cortex taking over. Furthermore, they noted that it is to make sure the "brain's visual cortex is stimulated". A consequence of the lack of input could be the degrading of the visual cortex. Some facts about the visual cortex are that it is located in the brain's occipital lobe, it responds to non-visual signals only when there is deprivation of visual input. The article mentioned that in blind people the occipital lobe will end up reacting to touch since there is no visual input. Eagleman and Vaughn also said neuroplasticity is a threat, neuroplasticity is re-wiring the less used places in the brain. They said this could be a possible threat because vision is not always active. The example they provided was if a person was in a dark place other senses may takeover, which is why dreams keep it active preventing the possibility of a takeover. The author mentioned that they do not agree with the theory, they mentioned dreams are associated with REM cycle of sleep which stimulates the occipital cortex. They also added that for the theory to be sound it would mean that the cortex is repurposed quickly. It said that humans have the most REM which leads to them maturing slowly than the rest of the primates. In the end the author mentions still more testing would need to be completed in order to make this theory more believable.
This week I read “A New Theory of Dreaming” by Neurosksptic. I really enjoyed the article because I never really understood why we dream in the first place. I believe that the theory was correct because it would make sense that dreams take place in order to keep our visual system active. I do understand why some people may not buy the theory, because there seems to be a lack of evidence in some areas. Lastly, I believe the hypnosis is a great idea because not only could it be tested easily, but it could answer all the questions that psychologists and neuroscientists have.
I've read the article on how zebrafish got it's stripes and when I read about the zebrafish getting their stripes, I have found something very fascinating about zebrafish that I had never knew about. The fascinating thing I had found in that article was that Zebrafish were used to study human diseases. Zebrafish have many genetic similarities and they also have a lot of physical characteristics such as major organs. They are very interesting to learn about in science because the show a lot of genetics similarities and physical characteristics to learn about for marine biologists. When I was still reading the article, the article states that " If we can understand what’s going on in the pattern development of a fish embryo, we may be able to gain deeper insight into the complex choreography of cells within embryos more generally." I find that very intellectual that learning from a very simple thing such as a Zebrafish's stripes can help with understanding diseases caused by disruption to cell arrangements within organs.
“A New Theory of Dreaming,” by Nueroskeptic explains The Defensive Activation theory in their opinion. Before this theory was explained, many psychologists and neuroscientists did not have a solid answer to the question, why do we dream. David M. Eagleman and Don A. Vaughn proposed the Defensive Activation Theory. In the article, this theory is defined as dreaming as a mechanism to prevent takeover of the visual cortex. Nueroskeptic states that they think it’s a highly original and creative theory, but he/she isn’t completely convinced. Eagleman and Vaughn’s theory is stated in the article like the role of dreams is to ensure that the brain's visual cortex is stimulated during sleep. Otherwise, if the visual system were deprived of input all night long, the visual cortex's function might degrade. The visual cortex is the brain’s occipital lobe. This lobe starts to respond to non-visuals signals if there is nothing visual in its input. The article provides an example of blind people. Due to the fact they can’t see, their occipital lobe responds to touch. The rewiring of the brain from sight to touch is a form of neuroplasticity. Neuroskeptic explains that neuroplasticity is generally good, but Eagleman and Vaughn believe that for visual systems, neuroplasticity can be posed as a threat. This is because vision is a sense which is active all the time. If people are in a dark place, like at night, there is no visual input, thus our visual cortex would be able to have another sense takeover in that time of vulnerability. So, due to the theory, when we dream, it’s the brain’s way of keeping visual systems alive. Neuroskeptic doesn’t buy this theory because dreams go hand in hand with simulation of the occipital cortex during a stage when sleeping called REM sleep. So, yes, dreams stimulate one’s visual system, but it is not their only job. Eagleman and Vaughn’s theory can also only make sense if neuroplasticity repurposing a visual sense to another sense happens rapidly. For the visual cortex to be defending neuroplasticity, the process would take a few hours. Eagleman and Vaughn do discuss evidence which can explain rapid neuroplasticity, but there is no evidence which shows that the rapid changes are strong enough to be harmful. They also show a correlation between the amount of REM sleep and the pace of the development of primate species. Primates whose babies tend to learn to walk and mature faster have less REM sleep. Thus, humans have the most REM, due to us being the slowest maturing primates. Basically, the faster the development, the slower the neuroplasticity, which means less of a job to protect the visual cortex from encroachment. The authors cite indirect evidence which states, “The present hypothesis could be tested thoroughly with direct measures of cortical plasticity.” Neuroskeptic believes that the hypothesis can be tested easily by taking human volunteers for a fMRI scan, at baseline, to establish the extent of their visual cortex and how visually selective it is. For 24 hours, half the volunteers would be blindfolded to produce visual deprivation. Half would have REM sleep disrupted that night, as well. At the 24 hour mark, they will get another fMRI scan. The author’s theory would predict that vision-deprived people would have a less visually selective cortex and the REM distribution would heighten this effect.
This week I read the article titled “Fish eggs can hatch after being eaten and pooped out by ducks”. It was interesting to say the least. I had never really thought about invasive species being spread through excrement, but this new study demonstrated it as a possibility. In Hungary, Orsolya Vincze, a biologist, and her team conducted an experiment involving thousands of carp eggs and eight mallard ducks. They discovered that 18 of the 8,000 eggs survived the journey through the ducks and remained viable in the ducks’ droppings. This was quite unexpected mainly because of how soft fish eggs are. Although it’s an oddly interesting discovery, this proves to be problematic because some carp species, like the ones the scientists fed to the ducks, are invasive species. As mentioned in the article, one carp can release thousands of eggs at a time, and there are a lot of water birds that are willing to feast on those eggs, making them a major method of transport for invasive fish species.
The other article I read discussed the new theory of dreaming. The article opens with the statement about the function of dreams and how it still remains a debate to this day. David M. Eagleman and Don A. Vaughn are then introduced along with their new theory about the purpose of dreams. Basically, they believe that dreams serve as a defense against neuroplasticity by keeping our visual system active so it’s not taken over by other senses. In other words, dreams occur to ensure that the brain’s visual cortex is stimulated while we sleep to prevent the degradation of the visual cortex’s function. This article was intriguing, and although I’ve never really pondered this question of what dreams do, their theory is quite thought-provoking. However, the author of the article expressed their disbelief of Eagleman and Vaughn’s theory. They argue that the theory only makes sense if neuroplasticity occurs both rapidly and harshly enough to actually do damage to the visual system. After reading the article, I began thinking about how many unanswered questions about ourselves remain and how interesting it can be to read about possible explanations to these questions.
The article I read today explained about different theories on why or how sealife, or “Zebrafish”, got their stripes. Many experiments have been done already to attempt to find a rationalization on this observation, and eventually there were propositions that there are certain pigments that spread more rapidly compared to other pigments in other wildlife. The spreading of pigments catches the concern of medical doctors because certain observations about pigments, stripes, dots, or any patterns on the bodies of sealift could result in new research for the medical field. Studying the outer bodies of the Zebrafish’s striking appearance may be relevant to medicine, since pattern formation is an important general feature of organ development, which can help treat diseases in the future.
The article “How the zebrafish got its stripes” informs the reader of the mathematical equation created by the University of Bath used to explain the origin of the fascinating stripes on zebrafishes. The article begins by discussing how animal patterns are generally created. It states that the arrangement of skin pigment cells starts during the embryonic stage of development which raises the attention of developmental scientists and mathematicians. Regardless of having little in common with mammals, zebrafish surprisingly have similar physical characteristics with humans such as major organs. This similarity is very critical as the information discovered relating to the pattern formation of a zebrafish could pave the way for future medical advancements involving diseases caused by a disruption to cell arrangements within organs. By specifically exploring the pigmentation of zebrafishes, and the singular movements of their cells scientists find it riveting that these same cells can form the zebrafish’s stripes during their embryonic stage. After understanding the pigmentation and how it is an emergent phenomenon, mathematicians at the University of Bath formed a mathematical model that could better understand pigment patterning systems, predict the pattern development of both wild and mutant fish and explore their similarity across different species. This equation has provided legitimate results and has cleared up some confusion regarding whether the zebrafish's unique cell movement relates to the formation of animal patterns. To conclude, the cells that form the interesting stripes on a Zebrafish have proven to be very impactful to the study of pattern formations as a whole.
The first article that talked about how zebrafish got their stripes, was shocking. Before, I did not know that patterns were anything more than different tones of pigment. First, I learned that in the animal kingdom, the arrangement of skin pigment cells starts during the embryonic stage of
development, making pattern formation an area of interest for scientists and researchers. I did not realize before that scientists had to start at the very first stage of fish development. I also did not know that zebrafish have genetic similarities to humans, despite not being mammals. Studying zebra fish's patterns are important because pattern formation is important to organ development. A better understanding of pigment pattern formation might give us insights into diseases caused by disruption to cell arrangements within organs pigment in zebrafish is an example of an emergent phenomenon, where cells can act according to their own individual rules, including self organization which leads to patterns. It is astonishing how scientists all over the world can use the zebrafish's embryo to analyze the choreography of cells. Stripes of an adult 'wild type' zebrafish are formed from pigment containing cells called chromatophores. Within the three types of chromatophores, all types shift around (self organization). I also learned how important it was to analyze data. Mathematical models can be used to incorporate the 3 cell types, and can predict the pattern development of future zebrafish.
The second article discussed a new theory of dreaming. Created by Eagleman and Vaughn, it states that the role of dreams is to ensure that the brains. Otherwise, if the visual system were deprived of input all night long, the visual cortex function might degrade. I have read many theories on why we dream, and this one was definitely intriguing and unique. To me, it made sense as our body has multiple defense mechanisms to keep us healthy. New study shows that neuroplasticity (the ability of the brain to form and reorganize synaptic connections, especially in response to learning or experience or following injury) could actually pose a threat because vision, unlike other senses, isn’t active all the time. Dreams could be our brains' way of defending the integrity of our visual system by keeping it alive. This means our visual cortex will never be “off”, and our visual sense would not degrade. The theory would only make sense if neuroplastic repurposing of the cortex happens very quickly, and there is no evidence to show that. In fact, there is barely any evidence to show that dreams are defense mechanisms for our visual cortex.Slower neural plasticity knees less need to protect the visual cortex, since only faster neural plasticity can invade. Overall, this theory was quite interesting, but I believe that there should be more evidence to support this hypothesis. Perhaps even an experiment could be involved.
The last article discussed how fish eggs can be hatched after ducks have eaten, then released them through the feces. I find it astonishing that fish eggs can enter, and be released from, a body and still be alive. According to a study done with mallard ducks and carp species, only 0.2% of the species were intact. Although only so little still remained alive, I am fascinated by even that percentage. Before, I had always thought that since fish eggs were soft, they would easily die in a duck’s guts.
In the article « A New Theory of Dreaming » the author introduces Eagleman and Vaughn’s idea about why people dream. Eagleman and Vaughn believe that dreaming is a mechanism used to prevent the takeover by the visual cortex during the time that the visual cortex is not otherwise stimulated. The author isn’t entirely convinced by this theory, they point out that neuro plasticity — which is when the occipital lobe is able to retire itself due to the deprivation of vision — is not considered to be harmful. See the theory only would apply if the neuroplastic repurposing of the cortex occurred quickly and at that rapid rate, the effects would need to be at a rate to cause serious harm. The known relation between dreams and the occipital cortex is that they occur during REM sleep. This means that dreams do stimulate the visual system, but there is no evidence as to whether or not its actual purpose is to protect the visual cortex. There is a potential experiment that can be done to test their theory though. They could use a group of human volunteers and observe their initial functionality of their visual cortes and then for 24 hours disrupt the REM sleep of half of them to see the differences in their visual cortex functionality.
I found the article, “A New Theory of Dreaming,” particularly interesting. As addressed by the article, dreams occur during REM (rapid eye movement) sleep. During this stage of sleep, your EEG, or brain waves, are similar to that of when you are awake, as well as some physiological functions such as heart rate and breathing. The only difference is your muscles are virtually paralyzed, which is how sleep paralysis occurs (when you wake during this stage, your mind enters a conscious state, but your body is still in a state of paralysis). There is not much difference in this stage that can account for neuroplasticity to occur other than the fact that there is a lack of visual stimulation. The researchers do bring up an interesting point about the functioning of the occipital lobe in the visual cortex, as it is usually correlated with vision, in blind people it is correlated with touch. When blind people dream, their perceptual experiences are usually not visual, which supposedly supports Eagleman and Vaughn’s theory that dreaming prevents the degradation of the visual cortex, and can lead to new pathways being formed to adapt to the minimal use. However, if the brain enters this cycle when you sleep, wouldn’t that be an indication that there is no need for the brain to adapt because it already alters its state when you sleep? Sleep is a part of the circadian rhythm that organisms possess, so it is a natural cycle. The brain might be used to when it falls into the sleep cycle so there would be no need for there to be a change in the neural pathways and synapses. It is an interesting theory, though I don't think it is the most plausible for the reason why we dream.
This week I read the article, “Fish eggs can hatch after being eaten and pooped out by ducks” by Carolyn Wilke. After initially reading the title I was immediately interested, but I didn’t realize how this discovery could have potentially solved the mystery of how isolated bodies of water become populated by fish. As the article says, fish eggs are really soft and it seems crazy to think that any could survive the acidic digestive tract of a duck, but the fact that 18 out of 8000 did in an experiment conducted by Orsolya Vincze shows that it is a possibility in the wild. I wonder if these eggs that remained intact will develop normally, or if there will be any problems with the fish as they grow. I would love to see this experiment be done with different species of fish to see if different fish eggs have a greater or lesser chance of surviving digestion, or if there are certain circumstances that increase an egg’s chance of survival. While reading about ducks pooping out eggs was interesting, the fact that it possibly explains how fish reach isolated waters is what truly amazed me.
This week I read “How the zebrafish got its stripes''. Overall the article spoke about the skin pigmentation cells and how they can be mutated making different patterns. The arrangement of these skin pigment cells begins in the embryonic stage. These arrangements create patterns, formations, and specific areas on the skin of animals. The zebrafish are used to study human diseases due to their genetics and major organs being so similar to humans. By understanding their appearance, it may help us understand diseases caused by disruption to cell arrangements within organs. Dr. Kit Yates explains how the different pigment cells act without coordinated centralized control, yet the cells still produce the stripe pattern on the zebrafish. These stripes are an example of a key developmental process and can help us further understand the complex choreography of cells while in the embryos. When mutations do appear they create a leopard, spotty, or labyrinthine pattern. I find this article interesting and would love to learn more about the zebrafish studies and theories. I wonder how the mutations the zebrafish has relates to what happens to us. I would like to know more about how the pattern might look if they’re in different parts of the world, environments, and more.
When deciding which article to read, the one titled “Fish eggs can hatch after being eaten and pooped out by ducks” instantly caught my attention. After reading it, it actually proved to be very informative as well as interesting. The discovery of fish eggs being able to survive after being eaten by ducks could be one of the ways isolated bodies of water can be populated by fish. This puzzled scientists for a very long time, as there’s no way for a fish to find its way into such a body of water. This discovery finally gives researchers a reason why fishes got there, because ducks can fly to other locations and poop the fish eggs out. The eggs could stay in the ducks body for up to 4 hours. In this time, the ducks could travel huge distances, and get to remote bodies of water. After further experimentation, it was found that .2% of eggs eaten by a mallard duck can survive and possibly hatch. Even with a low success rate, one fish can hatch many more fish, and populate a body of water easily. The possibility of this was disregarded prior to this research due to a fish egg’s soft shell. It was believed they’d be too fragile for such a possibility. This phenomenon proved that thought wrong, and showed me once again how complex and amazing nature really is. If I hadn’t read this article, I wouldn’t have known such a thing could happen.
The article "A New Theory of Dreaming", by Neuroskeptic discusses a newly proposed theory on why we dream. The author of the article finds the new theory proposed by David M. Eagleman and Don A. Vaughn interesting, but not fully convincing. The theory is mainly focused around the idea that the role of dreams is to ensure that the visual cortex in our brain is still active while we are sleeping. If it isn't active in our sleep, then the function might degrade. If the brain's occipital lobe, where the visual cortex is located, doesn't get any visual input, then it is prone to be taken over by our other senses. For example, blind people have an occipital lobe that strongly responds to touch because it lacks visual input. If the brain repurposes areas that arent utilized a lot, neuroplasticity happens. Neuroplasticity is mostly a good thing because the parts of the brain that we do not use a lot to develop a new role which will benefit the organism positively. However, the theory states that for the visual system neuroplasticity may be harmful. This is because unlike our other senses our vision isn't active all the time. For example, in the night or a dark place, we receive slight or no visual input. Therefore, dreams in a way keep this part of our brain alive so neuroplasticity does not occur. The author of the article then mentions that even though this theory is true, it may not be the main reason why we dream. Dreams are associated with the stimulation of the visual cortex during a stage called REM sleep, so they do help keep this part of our brain alive. However, neuroplastic repurposing does not happen very quickly. For the visual cortex to be in danger, harmful neuroplasticity would need to occur in the time frame of a few hours. Although the authors of the theory do include evidence to prove that rapid neuroplasticity can occur, they don't provide any evidence to show that these changes are powerful enough to be a threat. The theory does not include any evidence that shows that dreams act in defense. Instead, they claim there is a correlation between the pace of development and the pace of neuroplasticity. Primates who mature faster or develop faster have a smaller amount of REM sleep, and primates who mature slower have more REM. Humans are slowest maturing primates, so comparatively have more REM. Therefore, if the organism develops quicker, they have slower neuroplasticity which, means that they have less of a need to protect the visual cortex. The author of the article claims that this statement is purely circumstantial. She also mentions that the theory could be further tested with an experiment. If you take a group of human volunteers and give all them an fMRI scan to see the extent of their visual cortex, and then proceed to blindfold half of them for 24 hours, you could compare the visual cortex abilities of both groups with another fMRI scan. Eagleman and Vaughn's theory should show that the blindfolded group has less of a visually selective visual cortex and that the REM distribution enhanced the effect to be proven correct. In summation, this article was very interesting to read and I would like to see further results of this theory.
This week, I read the articles “A New Theory of Dreaming” by Neuroskeptic, and “How the zebrafish got its stripes” by the University of Bath
The first article discusses a new theory about why we dream. This theory by David M. Eagleman and Don A. Vaughn is from a preprint article which is a scientific paper that has not gone through peer review, which could make the paper inaccurate. Nevertheless, this theory is interesting.Researchers behind the theory believe that dreams are used to keep the visual cortex stimulated to prevent it from degrading. The article also discusses Neuroplasticity, which is when an underutilized area of the brain is repurposed. An example from the article pertains to blind people. Since blind people do not use the visual cortex, which is in the occipital lobe, the occipital lobe is rewired to respond to touch. In most cases, Neuroplasticity is a good thing, but when it comes to vision, it is not. Vision isn’t active all the time, which means it is at risk of being repurposed. Dreams help prevent this by simulating the occipital lobe when vision is not active. The author does not completely agree with this theory, and makes some valid points against it. For example, he says that for the visual cortex to need defending,Neuroplasticity would have to occur quickly. Although there is evidence that supports this, there is no evidence that shows it is harmful. They also discuss an experiment to test this new theory. The experiment requires a group of human volunteers to get a FMRI scan to use as a baseline for how selective the visual cortex is. The volunteers are blindfolded for 24 hours to simulate visual deprivation, and half the volunteers have their REM sleep disturbed. At the end of the experiment, another FMRI scan will be made. If the theory is correct, then the data from the second FMRI scan will show that the participants have a less visually selective visual cortex at the end of the experiment. This article got me interested in Neuroplasticity. I specifically thought about how neuroplasticity may relate to natural selection and evolution. Since neuroplasticity is a change in brain function as a result of external conditions, it is in a way a method of adaptation. Natural selection says that organisms better adapted to an environment survive longer, and reproduce, passing on desirable characteristics to offspring, and causing evolution over generations. Neuroplasticity causes our brains to evolve. This is explained in the paper “Allocating structure to function: the strong links between neuroplasticity and natural selection” written by Michael L. Andersen and Barbara l. Finley.
The second article discusses how researchers at the university of Bath created a mathematical model to explain how zebrafish got stripes. This study is very important, since they have genetic similarities with humans, and they also have most of the same organs we have. This study may also have implications on medicine, since pattern formation is important to organ development. It will help us understand the choreography of cells in the embryo. The article discusses how zebrafish stripes are caused by emergent phenomena, where individuals acting on their own rules are able to form a pattern. Examples of this include fish swimming in schools and sparrows.This phenomenon enables us to know exactly the process that is happening. In zebra fish, the pigment cells called chromatophores create the pattern without having a centralized control. The model predicts the development of the pattern by using information about the three chromatophores and their interactions. Their model can also be used to predict the pattern development in fish with mutated genes. Although there have been other attempts to create a similar model in the past, the other models were not able to account for mutations like the one created by the Bath University. Jennifer Owen, one of the scientists who created the model explains that the complexity of the model is the reason why it can predict the interactions between the cells of mutant fish.
This week, I read the first two articles provided. I found both articles very enjoyable to read, as they dive into very interesting topics that aren’t as important as the major events going on today. I found the first article, “How the zebrafish got its stripes” very fascinating and I was surprised that researchers are just finding this out in the present day. I was very astonished to learn that zebrafish have many genetic similarities to humans and include many similar physical characteristics, including most major organs. This is considering that this species looks completely different from our species, so it is difficult to identify them as similar. Also, studying the appearance of the zebrafish may be relevant to medicine in the future, by relating to their unique pattern, and may give a closer look into diseases that are caused by disruption to cell arrangements within organs. A new mathematical model helps to further explore pigment patterning systems. The pigmentation in zebrafish is an example of an emergent phenomenon, where cells can self-organize to form an ordered pattern at a much larger scale. There are many more examples of this in other parts of nature and biology. Dr. Yates, a mathematician who led the study, was fascinated by this discovery and states how the models can show the rules used for the cells to carry out their self-organization. Professor Kelsh, a co-author of the zebrafish study, had stated that it was important to find a correct mathematical model to explain the stripes on zebrafish because they are an example of a key development process. Precisely, if they can understand what occurs when the patterns develop when the fish is an embryo, then they will obtain more information on the complex choreography of cells within the embryos. Scientists have concluded that the stripes of a zebrafish are formed from pigment-containing cells, called chromatophores. These cells shift around the fish’s surface as they develop, and the cells interact with one another to create the patterns. When mutations occur in the cells, they result in distinct markings. I also read the article, “A New Theory of Dreaming”, which I found relatable, as I also wonder of the question of “Why do humans dream”. There have been many theories to answer this question, although there has been no accepted answer for centuries. Two researchers, David M. Eagleman and Don A. Vaughn, have proposed a new theory stating “The role of dreams is to ensure that the brain's visual cortex is stimulated during sleep. Otherwise, if the visual system were deprived of input all night long, the visual cortex's function might degrade.” Although neuroplasticity is considered a good thing, the two scientists express the fact that neuroplasticity could actually pose a threat to the visual system. This is because vision isn't active all the time (like when we are sleeping or in a very dark place), unlike our other senses. So, the visual cortex will produce dreams to keep the visual system active. I think this is a fascinating theory and it seems correct, but I am not very experienced in this topic, so the author doesn’t believe it. They express this by stating all the data that Eagleman and Vaughn haven’t provided and how there are missing points in the theory. The author also states that this theory can be tested easily by carrying out an experiment with human volunteers. From these articles, I have learned a lot about current events going on in the world that do not involve the global pandemic.
In the article “How the Zebrafish got its stripes” the University Bath has begun using a mathematical model to represent how Zebrafish obtain their striped pattern. This fascinating process is being studied by both developmental scientists and mathematicians to create this mathematical model. Scientists have discovered that the formation of this pattern occurs during the embryonic stage through skin pigment cells. They have found that the Zebrafish have a lot of physical characteristics that are similar to mammals, specifically similar organs. Due to the similar organ development scientists are looking into the pattern formations in relation to medicine. By knowing how the pattern forms in Zebrafish, scientists can have a better understanding of diseases in the organs that are caused by the disrupted cell arrangements. Overall the University Bath is fascinated by the phenomenon in which individual cells of the Zebrafish interact and arrange the striped pattern without a central control. The striped pattern is formed from cells called chromatophores that shift around and organize the pattern. However when mutations occur the cells do not probably interact and cause a spotty pattern. Understanding how this phenomenon works and the effects of mutations is a key part of understanding the developmental process which could be relayed to other species embryos.
Today I read, “Fish eggs can hatch after being eaten and pooped out by ducks” by Carolyn Wilke. After reading the article, I was shocked to learn that some fish eggs are able to incubate even after they are consumed by another animal. This was completely unexpected because I thought that the acid inside of the duck’s stomach would prevent this from occurring. One might think that it would be a bad thing for these ducks to consume these eggs because it could lead to a decrease of the fish population. In actuality, it helps spread their species to new isolated bodies of water that the fish would have been previously unable to reach. In addition, the spread of these eggs creates new food sources for other animals which allows new ecosystems to form and grow. Although the spread of fish into new environments can be beneficial, it is not always. For example, if you have an invasive species, such as a Common Carp, it could destroy the entire ecosystem. Any time a new species is added into an environment, the whole food chain could become disrupted. Overall, I found the article very informative and it makes me wonder if it is possible for other eggs to survive an animal’s digestive system. For example, if a snake ate a bird egg, would the egg be able to hatch after being processed through its digestive system? Only further research and observation can answer these questions.
I read the article of "A New Theory of Dreaming", and I was very fascinated by it. Eagleman and Vaughn's theory of the sole/main purpose of dreaming is that it is to prevent the takeover of the visual cortex of the brain due to neuroplasticity. This theory is incredibly interesting and might hold some truth to it, especially when they mentioned how a blind person's dreams are like. However, it does not seem to answer why our dreams are so extravagant and weird and why we get nightmares. If the sole purpose for dreams was so that we continue to have our visual cortex, why do we dream about living in different planets with mythical creatures or dining with the gods or being royalty in the midst of an alien war? Why do we have such weird and unique dreams that are both impossible and not real at all? I can tell you with firsthand experience that I have never seen a 5 eyed ogre-vampire hybrid, yet here I am dreaming about going on a duel with it to gain the attention of the royalty. Why do we need to get these dreams when the only purpose of it is to save the visual cortex? I can just as easily solely dream of my experiences and different paths each experience could have taken (which I do, but it isn't the only thing I dream about,and for me, it is the minority group of my dreams). How does me dreaming about an ogre-vampire hybrid benefit my visual cortex in any way. In addition, why do we get nightmares? The brain's purpose is to maintain the survival of the human, making sure that our heart beats blood, that our lungs take in air to breathe, that we get food into our stomachs to digest. A part of survival is mental health, and a healthy brain is one that has no imbalances in neural molecules, making the human relatively happy for the most part. We do not like bad things to happen to us and experience bad experiences; in fact, we go out of our way to avoid such traumas. However, nightmares seem to do the exact opposite. They bring out your worst memories and replay them in worse paths or they take a completely new experience that you have never experienced and enhance it to make you scared while you cannot do anything but sit back and watch it all happen to you. What is the use and purpose of nightmares and purposely damaging your mental health for a night when according to the theory above, we only have these to protect our visual cortex. Is it really necessary for me to experience a horrifying nightmare to protect that part of my brain? I highly doubt it. Because of both of the reasons I said above, I disagree with Eagleman and Vaughn's theory for why we dream albeit how interesting it may be.
I chose to read “A New Theory of Dreaming” by Nueroskeptic because the consciousness is something I enjoyed learning about in psychology last year. In class, we learned about the “activation-synthesis theory” stating that dreams occur because the hindbrain is activated during REM sleep and the cortex tries to make sense of these signals. On the other hand, David M. Eagleman and Don A. Vaughn propose their “defensive activation theory”: dreams are needed in order to ensure that the brain's visual cortex is stimulated during sleep. Otherwise, if the visual system were deprived of input all night long, the visual cortex's function might degrade. They think that due to the brains neuroplasticity, the occipital lobe containing the visual cortex will take on a new function. As pointed out in the article, this theory has a few flaws, as it suggests we would be losing function in our occipital lobe during the nighttime, since all we see is black so the visual cortex isn’t simulated. Additionally, the only evidence given for the defensive activation theory was that the correlation between pace of an organisms development and the percentage of time spent in REM sleep. However, when observing the scatter plots detailing the correlation between amount of REM sleep and the pace of development among primate species, I observed the coefficient of determination to be especially low at 0.32 and 0.17, meaning only 32% and 17% of the observed variation between the pace of development and present of sleep spent in REM sleep can be explained by the model's inputs. Therefore, the correlation that was regarded as evidence for this theory is actually very low, and does not do a great job of proving said point.
This week i read, “How the Sebrafish got its stripes.” scientists can study the pigment pattern formation of a zebrafish’s stripes to further understand disease that disrupt cell arrangement in organs. The cells that create these stripes are an example of an emergent phenomenon, hence they could act at their own will (independently). The chromatophore (pigment cells) organize themselves into the distinct stripes that we know today by interacting with the cells around them. But why is learning about the development of zebrafish stripes important? It is important because we can learn from fish embryos and apply that knowledge to embryos in general, including our own. something i found interesting was when their chromatophore mutated, they create more of a leopard/ dotted pattern. Luckily, the new model from the University of Baths accounts for these mutations to produce the best mathematical model possible.
In this week’s article, “How the zebrafish got its stripes”, researchers at the University of Bath created a mathematical model to describe how zebrafish actually develop their stripes. Throughout the article, there are many different facts and insights given about zebrafish. The one that I thought was most interesting was that studying their appearance and going more in depth with the research can help with medicine since zebrafish have many similarities with humans, including major organs. I found this interesting because even though they aren’t mammals they still have many genetic similarities with mammals that can help with medicine discoveries in the future. The mathematical model that was created in Bath is capable of discovering pigment patterning systems and similarities between different species. The mathematician that led the study into the development of a zebrafish’s stripes, Dr. Kit Yates, states how different pigment cells act without coordinated centralized control to produce the stripes that are on zebrafish. It is important for researchers to find an accurate mathematical model because the stripes are an important part for a developmental process. The pattern development can help give more insight on what is going on in the complex cells in fish embryos. Overall, in this article there were many unique and interesting facts stated about the zebrafish. With further development, there could be more discoveries made with different species that have similarities compared to the zebrafish which could help with other findings in other animals. The other article I read,“A New Theory of Dreaming”, informs readers about a preprint article that was written by David M. Eagleman and Don A. Vaughn suggested that dreaming was a mechanism to make sure the brain’s visual cortex is stimulated during sleep. They suggest that without dreams the visual cortex’s function could possibly reduce. The author talks about how neuroplasticity is usually a good thing but Vaughn and Eagleman’s research contradicts that statement. They claim that it can be a threat since it isn’t active all the time. Neuroskeptic claims that the theory doesn’t seem valid and there should be more research done before deciding that it is in fact accurate. Neuroskeptic proposes that the hypothesis that faster development means slower neuroplasticity which means less need to protect the visual cortex from encroachment could be tested by using human volunteers and splitting the testing in half. This article was interesting since there has been so much speculation about dreams but not one definite answer. This article just proves that point since both Vaughn and Eagleman’s theory was predicted to be invalid. Both of the articles were interesting and unique compared to other articles in the news about COVID-19.
I read the article, “A New Theory of Dreaming,” and found it to be extremely interesting. Written by Neuroskeptic, this article discussed a theory that David M. Eagleman and Don A. Vaughn proposed. They expressed that dreaming was enacted to ensure that the visual cortex didn't take over. This theory came to be because dreams cause the visual cortex to be stimulated during sleep and if not, its function wouldn't stay as sharp. The visual cortex responds to non-visual signals when deprived of forms of visual input, and the rewiring is considered a form of neuroplasticity. Eagleman and Vaughn thought that neuroplasticity could be looked at as a threat or dangerous and vision isn't always active. They went on to express that vision isn't active at night, therefore dreams are a way to preserve the visual system by keeping it activated while asleep. The author expressed that he liked the creativity of the theory, but was opposed to the idea that the stimulation of the visual cortex was the sole reason that dreams took place. The author believes that for harmful neuroplasticity to occur and the visual cortex to need defending, it would have to happen in a span of a couple hours. They weren't convinced that Eagleman and Vaughn showed evidence that these changes were harmful to that extent, and none of their evidence supports the idea that dreams occur out of defense. The author proposed an experiment to see if their theory was true or not, by observing a group of volunteers’ sleep. Each of them would have their visual cortex scanned and half of the volunteers would be woken up during the REM phase of sleep. Their visual cortex would be scanned, again. They would then be able to measure whether those who were woken up would have a less selective visual cortex. This theory was very interesting to read about, and I liked getting the opposing standpoint of the author as well. I think my views align with the author, in the sense that their theory sounds good, but it doesn't make sense that dreams occur solely out of defense.
This week, I read the article titled "How the zebrafish got its stripes" from the University of Bath. The article discusses the creation of a mathematical model to explain and predict natural phenomena, relating to pigment patterns, and its importance to the overall interactions within an embryo at a cellular level. A key barrier to success with previous mathematical models was the possibility of mutations, which would change the interactions between pigment-producing cells and result in spots or labyrinthine markings. In zebrafish, three types of pigment-producing cells are key to their much-studied patterns. Two of these such cells are melanocytes, which are composed of black melanin, and xanthophores, which contain yellow and orange carotenoids. The third type of pigment-producing cell is iridescent iridophores (S-iridophores are relevant to stripe formation, whereas L-iridophores maintain the pigment pattern) composed of reflective platelets (Hirata et al., 2003). Mutations amongst any of these cells could affect the self-organization process, resulting in altered pigment patterns. With the creation of this model, scientists can take into account the wide variety present in nature and continue to understand rarer pigment mutations. Since zebrafish and humans share 70% of their genetic material, it's logical that utilizing zebrafish as a living model can help researchers understand a multitude of human diseases related to pigmentation such as melanoma.
Additional Sources Consulted:
https://elifesciences.org/articles/52998#bib20
https://anatomypubs.onlinelibrary.wiley.com/doi/full/10.1002/dvdy.10334
The first article I read was “How the zebrafish got its stripes.” Upon first reading the article, I found it crazy that tiny little minnows, such as zebrafish, have several similarities with our species (such as the major organs). Although this study is interesting, it might not seem purposeful. In reality, the study of the formation of patterns in certain mammals is extremely useful, as pattern formation is a feature that is prominent with the development of certain organs. Therefore, this study can further provide information about organs and diseases that possibly develop with growth. University Bath created a mathematical model in order to further understand pigment patterns. The stripes of a zebrafish are an example of an emergent phenomenon, according to the article, which means that a zebrafish’s cells act according to their own regulations yet still self-organize into a much bigger pattern unintentionally. The mathematical model is important because it highlights an important step in the embryo development which leads to these pigment patterns. The article talks about chromatophores, which are cells that arrange to form the stripes of a zebrafish. As the fish grows, these cells further organize themselves into the prominent pattern which the fish is named after. It is known that the zebrafish’s pattern occurs because of the three types of chromatophores which self-organize. I did not see an importance of creating a model for why the zebrafish has stripes, but after reading I understand that the model can help understand mutations that can occur within the cells of zebrafish. I never really gave much thought to the process of how patterns form on any animal, not just zebrafish, but the intricacies of how these patterns form are interesting. The second article I read was “Fish eggs can hatch after being eaten and pooped out by ducks.” Despite the strong acid and the long journey experienced by fish eggs swallowed by ducks, some eggs are able to survive and therefore hatch. Although at first glance this study might seem pointless, it is one of the reasons that can contribute to why fish are found in certain remote bodies of water. It is mind boggling to me that people are creative enough to perform a study to find out if this is a contributing reason as to how isolated bodies of water have fish in them. Thinking logically, it makes sense though, considering ducks can travel several kilometers before the fish eggs are excreted. In the study, only 18 eggs hatched out of the 8,000 which may not seem like a lot in the grand scheme of things, but over time and with multiple ducks, it would add up. I thought fish eggs were fragile and definitely not strong enough to surpass a duck’s system, but clearly according to this article I was wrong.
The first article I read this week from the University of Bath entitled “How the Zebrafish Got its Stripes” informs readers about a mathematical model that researchers have developed to see how this species forms it's stripes and how this information can be used in beneficial ways in the medical and scientific field. Although it seems unlikely, these fish have a number of genetic similarities to humans, including major organs. It is mentioned that the arrangement of skin pigment cells begins during the embryonic stage. According to the article, pattern formation is a key feature to organ development which means understanding pigment pattern information, like that of the zebrafish, can give us information on diseases that are caused by the disruption of these cell arrangements. The model is used to study pigment patterning systems, and the pigmentation in zebrafish is an emergent phenomenon which means that the cells act according to their own rules. This was studied by Dr. Kit Yates to determine how these individual pigment cells produced striped patterns in zebrafish without a centralized control system. Robert Kelse, a co-author on the study, explains that it was important to understand this process because it would provide us with deeper insight as to the choreography of cells in the embryo in other organisms as well. The stripes in zebrafish are formed from chromatophores, which are pigment containing cells, and mutations that occur as these cells shift around is what results in alternative markings, such as leopard skin. The scientist, Jennifer Owen, who is responsible for the creation of the mathematical model believes that because of the model's complexity it can help predict other developmental defects and predict cell to cell interactions. It is extremely intriguing that the pattern and the small fish can tell us so much about the general understanding of embryonic development. With this discovery, I can only believe that there is similar research to come with other patterns that can possibly give us a better understanding of mutants and diseases in the vital organs within mammals. In the future it may be possible that with further advancement on the research with zebrafish and other patterned animals that cures or medical advancements can be developed to help these diseases and mutations. Staying on the animal studies, the next article, “Fish eggs can hatch after being eaten and pooped out by ducks,” by Carolyn Wilke definitely caught my eye the most. The article talks about how fish eggs, as delicate as they may be, are able to survive through a duck’s digestive tract and exit through its excrement, contributing to the spread of invasive species. Even though in Orsolya Vincze’s study where birds were fed hundreds of fish eggs within a lab only 0.2 percent of the eggs remained intact after making it through the bird’s guts, it's still extremely surprising they survived at all. It took from one to four hours from consumption to poop out the eggs and especially for migratory ducks, that means these eggs can be spread far from their original “habitat”. This poses so many questions in my head as to how this is even possible. The duck would have to not puncture said egg as it consumes its food and then the egg would have to make it through the entire digestive tract completely unscathed and hatch out of the bird’s excretion. This process was possible within a lab, but it's still unsure if this process would even be possible in the wild. If so, it would explain certain invasive species. If the birds are able to do this in the wild on their own, is it possible that an egg can hatch while it is still inside leading to a live birth as the bird excretes? From the articles I read today, it is clear to me that even with all the research we have on animals, even common species, there is always more to wildlife. I can only imagine how much more there is left for us to discover that can lead to so many medical or scientific advancements to better our society as a whole.
In the article "Fish eggs can hatch after being eaten and pooped out by ducks" by Carolyn Wilke. This article indulges on the topic of fish eggs being eaten, and then exit through the rear end of a duck, which allows for possible invasive species to locate in a different area. It is hypothesized that the reason fish are found so far out in different bodies of water, is because of ducks unknowingly transporting fish eggs do isolated parts of earths water bodies. Many scientists do not believe that this could be possible, but a study conducted by Vincent and her colleagues found that about 18 in 18,000 eggs were intact after defection. Most of the eggs took about an hour to pass, with an outlier taking 4 hours to pass. In this amount of time, the duck can travel a reasonable amount of distance. It is noted the even though the survivor to death ratio is low, these numbers can add up depending on how many ducks consume fish eggs, as well as the amount they consume. Overall i found this article to spark a rather interesting conversation, in which a good amount of research can solve.Not only do i like the article because of the title, but also because of the valuable knowledge it has enlightened me with in my weekly readings.
"Fish eggs can hatch after being eaten and pooped out by ducks" was an unusual, interesting article. It reports on a study conducted by scientists where thousands of eggs of two invasive fish species were fed to ducks and their fecal matter was subsequently examined. While only a small percent did survive after passing through the duck, this percentage still accounts for a large number of fish eggs surviving since fish lay thousands upon thousands of eggs. Since this was only an experiment, it is still unclear if this realistically occurs in nature. However, it does suggest that fish eggs are much sturdier than their soft exteriors say. The second article I read was "How the zebrafish got its stripes." It has been known that zebrafish are a good model for studying human diseases since they share many of our major organs. Analyzing their beautiful skin pigmentation patterns may help develop medicines later on, for pattern formation is a feature of organ development. The University Bath has developed a mathematical model designed to explain how a zebrafish develops its intricate pattern of stripes. By understanding how individual pigment cells coordinate to form clear stripes, we can better understand the coordination of cells in embryos. Chromatophores are the pigment-containing cells in zebrafish, and they shift around as the zebrafish grow until they form the stripes. The model has been able to successfully predict pattern developments in wild zebrafish. It has also been able to predict mutated patterns based on how cells interact with each other, proving the sophistication of its design.
Imagine being a fish egg, getting eaten by a duck, and surviving. Pretty weird, right? That’s how I felt when I read this weeks article “Fish Eggs Can Hatch After Being Eaten and Pooped Out By Ducks” by Carolyn Wilke. Have you ever came across an isolated body of water (a lake) and seen it densely populated with fish? One theory suggests that fish eggs can still hatch after being digested by the duck. In one study, thousands of fish eggs were fed to mallard ducks. 0.2% survived. It’s shocking to learn that eggs can remain intact after being bombarded by the digestive fluids of the duck. However, this may also be a point of error in nature. A minuscule 0.2% can also signify that the duck simple missed the eggs, which allowed them “safe passage” through the excretory system. Most viable eggs were pooped out within the hour, while one took a 4 hour journey in a not-so-pleasant spot.
This week I found the article “A New Theory of Dreaming,” by Neuroskeptic very interesting. As mentioned in the article, the function of dreams has been greatly discussed over the years. David M. Eagleman and Don A. Vaughn proposed a new theory regarding dreams in which they claim that the purpose of dreams is to ensure that the visual cortex is stimulated during sleep. This is because if the visual system were deprived of input all night, then the function could degrade. It is known that the visual cortex could respond to non-visual signals if it does not have visual input. This is proven in blind people's brains in which their occipital lobe strongly responds to touch because their visual cortex is under-utilized. This is known as neuroplasticity in which underutilized brain areas are rewired. According to Eagleman and Vaughn, neuroplasty could be negative in terms of the visual system. Because it is not used at night, our visual cortex could be dominated by our other senses. This is why dreams are used to keep our visual system working and active. Neuroskeptic does not buy this theory because although dreams stimulate the visual system through REM sleep, they are not convinced that it is the main purpose. Neuroskeptic claims that the theory would only make sense if neuroplasty happened very quickly. Although Eagleman and Vaughn talked about evidence regarding rapid neuroplasty, there is no visual evidence. As a result, Neuroskeptic believes that the theory needs to be further tested with a group of human volunteers and an fMRI scan. Half would wear a blindfold while the other half would have REM sleep disrupted at night. While the theory proposed by Eagleman and Vaughn is fascinating, I agree with Neuroskeptic in the sense that there are a few holes within the theory. It needs to be further tested and more visual evidence needs to be found in order for the theory to be proven.
I learned a lot about the zebrafish after reading the article, “How the zebrafish got its stripes.” I found it extremely interesting that the zebrafish can be useful when studying human disease because they seem to have nothing in common with the human body (at least externally). As it turns out, the zebrafish has a similar genetic blueprint, as well as similar organs, to the human body. The fish appears to have stripes because the pigment cells in its skin organize themselves collectively to form a pattern, which is an emergent phenomenon. It is important to pay attention to the stripes on a zebrafish because they represent a developmental process. If scientists are able to comprehend the formation of the fish’s pigment cells, then it will allow them to understand other parallel developmental processes of embryos.
The article, “Fish eggs can hatch after being eaten and pooped out by ducks” was also a very interesting read. When the ducks eat the fish eggs, some of them are able to survive the stomach acids and escape through the duck’s excrement. This is actually beneficial to the environment because it helps to disperse invasive species into different areas. Although a very small number of the fish eggs are able to survive being eaten by a duck, they are still spread to different areas and hatched (especially because ducks are migratory birds).
The most unexpected revelations can come about through experimentation. It’s a known fact for ages that species travel and pop up in unexpected places. Many scientists have wondered- how? How is it possible for invasive species to go from their home to a whole new continent. Scientists believe they have found a way that fish travel- through the gut of ducks. In “Fish eggs can hatch after being eaten and pooped out by ducks” by Carolyn Wilke, the article discusses how fish eggs can be found viable in mallard duck excrement. Wilke writes about research done by Orsolya Vincze, an evolutionary biologist. Vince and his team fed eight mallard ducks thousands of eggs from two carp species. The data revealed that about 0.2 percent of ingested eggs survived. In the surviving eggs, some contained wriggling embryos and a few eggs hatched. However, scientists are still unsure whether eggs can survive in this way in the wild. Although the number of surviving eggs is low, many migratory birds could travel spreading fish eggs to isolated bodies of water. Even though the article’s headline was bizarre, interesting results can explain age old questions.
The concept of dreaming has always interested me, even as a child. It is fascinating to me as to how the human body is capable of creating these scenarios and events that are figments of our imagination but feel as though they are reality, not to mention why dreams occur in the first place. Recently, David M. Eagleman and Don A. Vaughn have proposed a theory called “The Defensive Activation theory: Dreaming as a mechanism to prevent takeover of the visual cortex”. The theory is yet to be published and is currently shared to the public as a pre-print. This theory is further explained and discussed in the article, “A New Theory of Dreaming” by Neuroskeptic. Eagleman and Vaughn’s theory essentially states that dreaming protects our visual cortex by stimulating it in our sleep. This is because it is possible that the visual cortex, the region of the brain that receives, integrates, and processes visual information relayed from the retinas, may deteriorate if it is not used throughout the course of the night. It is possible that the visual cortex can “rewire” itself to also respond to non-visual signals if it is bereft of visual signals. The act of rewiring areas that are not being used as much as they should is known as neuroplasticity. Neuroplasticity in regards to the visual system can be detrimental due to the fact that our sight is used less often than any of our other senses. Anytime that we are in an area that is dark or it is nighttime, we are not able to use our sight fully. Allegedly, our visual cortex would be vulnerable to an attack of sorts conducted by the other senses and, according to the theory, dreams help protect the visual system from this by keeping it stimulated throughout the course of the night. The theory, however, does potentially have some faults, the biggest being the speed of the repurposing of the visual cortex. In order for dreams to have the need to protect the visual system, the repurposing or harmful neuroplasticity of the visual cortex must happen over the span of a few hours; otherwise there is essentially no need for dreams to be a “protector”. To support their theory, Eagleman and Vaughn stated that primates with babies that develop and mature quicker tend to have more REM whereas humans tend to have less REM. They stated that the faster development of a species means that there is slower neuroplasticity, basically meaning that there is not that great of a need to protect the visual cortex. A way to test their hypothesis is to have a group of volunteers who get a baseline fMRI scan to determine how well their visual cortex responds to visual stimuli. Then, throughout the course of a full day, half of the volunteers will have a blindfold on and half of them will have their REM sleep disrupted. After the 24 hours, at which point the volunteers will receive a second fMRI, the volunteers that were blindfolded will have had a less visually selective cortex if their theory is indeed correct.
The first article I read this week was “How the Zebrafish Got its Stripes.” This article begins by mentioning the deep rooted fascination many scientists share in regards to animal pigmentation and its causation. Researches at the University of Bath have recently made progress towards an explanation for animal patterns; they devised a mathematical model that explains how the zebrafish got its stripes. The stripes on a zebrafish are caused by an emergent phenomenon. There are different types of emergent phenomena but in the case of the zebrafish, its cells are able to act on their own accord—they can “self organize”—and arrange themselves in prominent patterns at large scales. Though the explanation of how the zebrafish got its stripes may seem trivial and insignificant, this newly acquired knowledge may be useful for further understanding other animal patterns. I was drawn to another article by the promising headline on our class page and I was not disappointed. The second article I read this week was “Fish Eggs Can Hatch After Being Eaten and Pooped Out by Ducks.” I found this article very interesting because it is about something that I didn’t even know was possible, let alone actually occurred. Apparently, water birds that ingest fish eggs may spread said eggs dozens or even hundreds of kilometers apart. Some of the eggs that have been ingested stay intact once excreted and hatch. Though the survival rate of these eggs remains very low, those that do hatch may add up and the water birds that “transported” them could potentially be responsible for spreading the fish population.
For this week's assignment I read all three interesting articles assigned. The first article was called “How the zebrafish got its stripes”, constructed by a research team at the University of Bath. This team of scientists has been able to construct a mathematical model which explained how the zebrafish developed its stripes. While on the face of it, it may seem insignificant, zebrafish are extremely important to studying human diseases due to their similar genetic and physical characteristics to us, and the formation of patterns is essential to organ development. Therefore, studying pattern formation in zebrafish will allow us to understand diseases caused by the incorrect pattern formation in our organs. Patterns like the ones that form on zebrafish are examples of an emergent phenomenon where cells or individuals can self organise to form a pattern. Understanding the embryonic development that leads to these types of patterns will give more insight on the formation or structure of embryos in their entirety. Specifically to zebrafish, the stripes form from pigment cells called chromatophores which moved around to create their patterns. Mutations would result in splotchy leopard like patterns rather than the linear shape most commonly seen. The model made to determine the pattern formation result has proved successful in both wild type and mutated zebrafish. The next article I read was entitled, “A New Theory of Dreaming” by user Neuroskeptic. This article is almost a personal review on the research paper and theory proposed by David M. Eagleman and Don A. Vaughn, called The Defensive Activation theory: Dreaming as a mechanism to prevent takeover of the visual cortex. To summarise the paper, dreams stimulate the visual cortex during sleep as a mechanism to prevent the degradation of visual cortex function. The writer is not sold on this paper saying that while everything they wrote is scientifically true, he’s not sure it is the prime reason for dreaming. The paper discusses how the rewiring of specific areas in the brain, called neuroplasticity, can occur if dreams don’t occur during sleep, however they do not mention how this could be harmful. The paper lacks sufficient testing however it does seem to have some truth surrounding it, however like the author of the article I’m not sold on this due to that lack of evidence. Finally, the last article I read was called, “Fish Eggs can hatch after being eaten and pooped out by ducks.” This wasn’t as shocking as it was kind of hilarious. After being consumed by a duck, not all of the small fish eggs are eaten. About 0.2 percent of ingested eggs, 18 of 8,000, were intact after defecation in a lab experiment. While the numbers are low, its still plausible for duck feces to spread populations of fish, and i stil can’t believe I managed to make poop jokes uninteresting. This was a much needed break in the consistent development of COVID-19 related news, and provided great insight on the scientific world.
This week the article "How the Zebrafish Got Its Stripes" by the University BATH, discusses exactly what the title states. Skin pigment cells develop during the early embryonic stages in the animal kingdom. Zebrafish are freshwater minnows and although look far from relative to mammals, their genetic makeup is quite similar to us. Pattern formation is an important feature of organ development, and understanding this allows us to learn how diseases are caused by cell disruption in organs. The pigmentation in zebrafish is an example of a phenomenon where cells act on their own rules and organize to form a pattern locally. Dr. Kit Yates states, "Our modeling highlights the local rules that these cells use to interact with each other in order to generate these patterns robustly." Professor Robert Kelsh explains that its important to find a mathematical model explaining the stripes bc it is an example of the developmental process. Being able to understand the pattern development in fish embryos, allows us to gain a deeper understanding into the structure of cells in embryos. The stripes of a zebrafish are formed by pigment cells, chromatophores. There are 3 types of chromatophores, shifting around an animal's surfaces as they interact with one another. Sometimes mutations can occur, which can change how the cells interact during developmental stages in an embryo. The University or BATH developed a mathematical model inclusive of all three cell types and interactions. This turned out to be successful, allowing scientists to predict the pattern development of wild and mutant fish. Jennifer Owen explains that its important to understand pattern development to be able to predict development mutations that are lesser understood. This allows scientists to be able to predict and prevent as soon as possible w the knowledge of early embryonic development.
The article, “How the Zebrafish got its stripes” not only explained how the Zebrafish got its stripes but also the similarities between humans and the fish. For example, Zebrafish have similar major organs as well as genetic similarities which make them helpful when studying human disease. The Zebrafish got their stripes from self-organizing cells that form the patterns. Chromatophores, pigment containing cells, are the cells that self organize to create the patterns. A new mathematical model has allowed scientists to predict patterns through local rules they have discovered. The article, “A New Theory of Dreaming,” talks about a theory two scientists developed to try to explain why dreams occur. This theory is based on the idea that dreams occur to make sure people’s visual cortex doesn’t degrade. The reasoning behind this theory is that if dreams don’t occur then the neuroplasticity of other senses will take over the visual system. Although interesting this theory hasn’t been proven, experiments are being developed to determine if the theory is true or not. The last article, “Fish eggs can hatch after being eaten and pooped out by ducks,” talks about a discovery that could change sea life. This article presents a new finding that some fish eggs can be pooped out perfectly fine after being eaten by a duck. This could mean that the duck could transfer the fish to other places where those types of fish weren’t seen. Although the ducks get rid of the fish eggs in about an hour ducks can travel to other locations to discard the fish.
I read the article, “How the Zebrafish got its stripes”, and this article was talking about the different animal patterns that are present in nature. Scientists at University Bath made a mathematical model to explain how the zebrafish gets its stripes. This model is very important to understanding pigment patterning systems, and similarities between other species. Zebrafish are a type of freshwater minnow and they are used for studying diseases between humans because they have a lot of genetic similarities with humans, as well as physical characteristics such as organs. The stripes of zebrafish are made of cells called chromatophores, as the organism continues to develop they will shift and interact to self organize into the stripes pattern. Many researchers and mathematicians have been trying to find an explanation for how the zebra fish’s stripes form for many years, but this model has made it possible to see how the patterns will form in wild fish and mutant fish.
The purpose of dreams are still unknown in the scientific community. A recent theory was made to explain why we dream. The theory stated that the visual cortex would degrade if it’s not constantly stimulated. Why this logic does make sense, there are some holes in the theory. In the dark, there is no visual stimulation, so the brain requires the cortex to react to other senses such as touch. However, it is interesting to believe that dreams are meant to protect the brain. ( this is a little off topic ) but let’s say dreams ARE made to protect the brain and functions, then why do people get nightmares so terrifying that they are traumatized?
Anjana
This weeks article was titled “How the Zebrafish got its stripes.” The article starts off explaining all animal patterns. It says how the stripes spots and rosettes seen in the wild or a source of endless fascination and how researchers have developed a mathematical model to explain how one important species, the Zebrafish, develops its stripes. The article then goes on to state how in the animal kingdom the arrangement of skin pigment cells starts during the embryonic stage of development making pattern formation an area of keen interest not only for scientists but development biologist and mathematicians as well. The article continues on how a zebrafish may also be able to provide fundamental insights into the complex process that underpin biology and how in time studying their appearance may be relevant to medicine since pattern development is important to organ development. As we continue into the article a new math medical model devised in Bath is shown to us. This will be for further exploration into pigment pattering systems. The article finally comes to conclusion by talking about two final points. Scientists know a lot about the biological interactions needed for the south organization of a zebrafish is pigment cells but there are has been some uncertainty over whether these interactions offer a comprehensive explanation for how these patterns form. The second point being how mathematicians have been trying to explain how zebrafish stripes for for many years that have never been able to know why because they’ve never been able to account for the broad range of fish mutant patterns, but now thanks to Jennifer Own we can now help to predict the developmental defects of some less understood mutants. Some examples of this are the cell cell interactions that are defective in mutants such as leopard which displays spots. All in all this was a very interesting read. I really enjoyed reading the article on “How the Zebrafish got its stripes” and how this can lead to the understanding of less understood mutations.
The article I found most interesting was "How the zebrafish got its stripes." The article discusses how animal patterns are a source of endless fascination. Scientists and researchers have just discovered how zebrafish got its stripes. Before zebrafish in the animal kingdom, skin pigment cells start during the embryonic stage of development, which patterns begin to form. The reason why researchers study zebrafish is that it may be relevant to medicine. I've learned that pattern formation might give us insights into diseases caused by disruption among organs. An emergent phenomenon is when one in which individuals (cells in this case), all acting according to their own local rules, can self-organize to form an ordered pattern at a scale much more massive than one might expect. An example of this would be synchronized swimming among a school of fish and pigmentation in zebrafish. It's essential to find the correct mathematical model because patterns are exciting and beautiful in their own right and an example of critical developmental processes. The stripes of an adult zebrafish emerge from pigment-containing cells called chromatophores. As the animal develops, these pigment cells shift around on the animal's surface, interacting with one other and self-organizing into the stripy pattern for which the fish are named. In conclusion, mathematicians have been trying to explain how zebrafish stripes form for many years; however, many previous attempts have been unable to determine from the broad range of observed fish mutant patterns.
This week I read "A New Theory About Dreaming". This immediately caught my attention because I find psychology and neurology very interesting. I am amazed every time I learn something about the thousands of functions the brain is doing while we are asleep. For example, how the body enters a state of paralysis while dreaming or theories about how everything and everyone we dream of is something we have seen in real life because that's just how much sensory processing our brain does even if we can't consciously recall it. However, I would not have guess that dreams were a form of defense against degrading. I agree with the author that this could be a function of dreaming, but it may not be the main function. Since our brain is still very active during sleep, it seems hard to believe that it could degrade so quickly. It was interesting to find out that in theory, our visual cortex can be taken over by other sense- I didn't know that was possible. I learned about specific details about neuroplasticity, such as that it can not occur so quickly in a few hours. This makes me wonder what factors contribute to neuroplasticity and how long would it usually take? How much does it have to do with aging, the environment, genetics or simply the individual? The correlation on the graphs essentially meant that faster development means slower neuroplasticity so less need to protect the visual cortex. However, I think there are too many other factors that could've affected the primate's maturity. It could be very helpful to do a more specific study on humans like the author suggested towards the end. This would help make this claim more supported with hard evidence.
With the world constantly growing in discoveries, new research is able to answer several questions that arose from the study of skin pigment cells and their interactions. In the article, “How the Zebrafish got its stripes,” published after a study held by a team in the University of Bath, I learned that there is a link between pattern formation and organ development for feature-like purposes. Due to this link, teams involved in medical research about diseases are better able to understand a disruption between cell arrangements within organs (ex: heart) that result in a disease. The beauty of simple to complex processes in science opens the mind to the great possibilities yet to learn. For instance, Zebrafish pigmentation is a type of emergent phenomenon in which cells, in simple definition, are able to self-direct themselves into an organized fashion to produce a specific pattern. However, like ever new discovery, the research won’t end until every possible question can be answered in relation to how Zebrafish obtain their stripes and its benefit to the scientific community. The second article I read, “Fish eggs can hatch after being eaten and pooped out by ducks,” I figured that death may not be so inevitable in certain scenarios. With the spread of fish who survive from the gut of ducks, there will most certainly be a change in the allele frequency in the community it is forced to settle in, however, whether their addition in the community is healthy for their population and environment is dependent on their selective adaptations. Hundreds of years later, evolution may even allow fish to adapt in environments that would be a shocker to those who lived in the past, who knows? The great factor about science is that it can get a little funky here and there, which makes it all much better to get involved in.
This week for AP Bio, I read “how the zebrafish got their stripes”. researchers from the University Bath developed a mathematical program to predict natural phenomena such as stripes or spots on an animal. Because pattern development is a major part of organ development, studying these natural phenomena could help us learn more about diseases and other disorders. These new programs can predict patterns in pigmentation. The zebrafish have three different chromatophores that self-organize and result in the stripe pattern of the zebrafish. Different mutations could even result in a labyrinth or maze looking pattern. Professor Robert Kelsh summed it up by saying its important to learn about these patterns “Partly, because pigment patterns are interesting and beautiful in their own right. But also because these stripes are an example of a key developmental process. If we can understand what's going on in the pattern development of a fish embryo, we may be able to gain deeper insight into the complex choreography of cells within embryos more generally."
In my opinion, the most intriguing of the three articles was, "Fish eggs can hatch after being eaten and pooped out by ducks." The article gives insight into other ways, besides humanity, invasive species get into the environment. Due to the strange properties of the eggs, it could mean that these species of fish have evolved so their eggs may survive their predators' digestive systems. It brings into question if our current ecosystems are made up of formerly invasive species that became a normality in these environments. Species to take into consideration if they were formerly invasive are those that have many offspring in one reproductive conception. Similar to the fish, these children would mostly die, however, the few that survive would invade their new environment. The article's questions are what drew me to it as we may have to rethink our whole ecological movement against invasive species and come up with new ways to handle invasive species in the future.
In the first article I read this week, “How Zebrafish got its Stripes,” published by the University of Bath explained animal patterns seen in nature (stripes and spots). The university developed a mathematical model to understand how zebrafish obtain their stripes. The fishes share similar genetics and physical characteristics to mammals, as a result they are relevant to medicine. Studying their appearance and pigment pattern formation can inform us about diseases about organ arrangements. An example of the development process are the stripes. If we understand the pattern development, we can learn the intricate choreography of cells in embryos. The Bath team has created a model of the three cell types and how they interact to predict future patterns. The scientist, Jennifer Owen, is accountable for the model which can help predict the defects to mutants that weren't understood before.
The second article, “A New Theory of Dreaming,” reviewed by Neuroskeptic was a review on David M. Eagleman and Don A. Vaughn’s new theory about dreaming. They believe the brain’s visual cortex is simulated during the 6-10 hours of sleep. Without dreams, the function can negatively be affected. However, the author is skeptical of the theory and is convinced the sole purpose of a dream is not for the stimulation. Neuroskeptic explains the theory would make more sense if the neuroplasticity had a harmful effect over a period of time, however, there was no evidence to support that. They compared the amount of REM sleep and the time of development among primate babies. The faster the babies’ development, the slower the neuroplasticity, which leads to less need to protect the visual cortex. The reviewer believes to test the theory, they would need a group of humans to take an fMRI scan (to scale the visual cortex). After 24 hours half of the group would blindfold themselves to stimulate visual deprivation. Half of the group would get REM sleep disrupted to enhance the effect. In the end, they would have to take another fMRI scan to see if they had a less visually selective visual cortex. All in all, I was fascinated with the theory and I enjoyed the contrasting review given by Neuroskeptic, however, in order to make a definitive judgment on the theory more evidence and tests would need to take place.
In the article "A New Theory of Dreaming" by Neuroskeptic, it talks about how and why we dream, as well as what could it represent. To this day neurologists still don't have an accepted answer to this age old question. A new theory has been proposed, and dreaming is just a mechanism that the mind made up to keep the visual cortex in top shape. if it is deprived of visual input (seeing things) then it may respond to non-visual signals. In general neuroplasticity is an amazing feature to improve the brain, however when it comes to the visual cortex it becomes a threat to our vision. This is a good theory, however it simply doesn't make sense. dreams do still affect the visual cortex, but that isn't the purpose of them, their theory only makes sense if neuroplasticity happened at an extremely fast rate. Although it can occur within a few hours, it has not been proven that it is harmful. This is a very interesting topic as dreams are still one of the unsolved mysteries in the science community. This specific theory can be tested easily. take an fMRI scan, from multiple volunteers to see how selective their visual cortex is. Then have half of the volunteers wear a blindfold to produce visual deprivation, and have the other half, have REM sleep, both for 24 hours. and at the end they both get an fMRI scan to determine how this has effected their brain. Overall this is a very interesting topic and one could dive very deep into how vast and unpredictable the human brain is.
This week I chose to read the article, “A New Theory of Dreaming” written by Neuroskeptic and was quite fascinated by it. The author of the article writes about David M. Eagleman and Don A. Vaughn’s theory on why we dream. The scientists hypothesize that the reason we dream is to ensure that we stimulate our visual cortex while we are sleeping to prevent it from degrading over time. Scientists know that the visual cortex, located in the brain’s occipital lobe, can respond to non-visual signals if there is no visual input. This is a phenomenon that occurs due to neuroplasticity, the trait that allows the brain to repurpose un-utilized or under-utilized areas. Neuroplasticity has its benefits, however it can be detrimental because not all your senses are active all the time, particularly vision. Eagleman and Vaughn hypothesize that in order to prevent the visual cortex from being “taken” over by other senses every night, we dream. If we didn’t dream, as Eagleman and Vaughn claim, the integrity of our visual system would degrade over time as a result of a period of dormancy every night. Although, as pointed out by the author, there are a few flaws with this theory. The author points out that for Eagleman and Vaughn’s theory to make sense, neuroplasticity has to occur really quickly. For the visual cortex to need defending, the brain would have to harmfully repurpose the cortex in a matter of a few hours, which seems unfeasible. Eagleman and Vaughn base their theory on the fact that primates that develop faster have a slower neuroplasticity; this means that humans, the slowest developing primates, have a faster neuroplasticity. However, there is no sufficient evidence that proves said point and an experiment that tests this theory has not been carried out. I personally think that this theory is flawed due to the nature of our dreams. Our dreams generally revolve around our desires, subconscious feelings, abstract thoughts, etc. If our dreams were truly about maintaining our visual cortex, why would they not be realistic, revolving around our everyday day life instead. The reason we dream of our subconscious desires and thoughts is likely a method for our brain to cope with pressures of our everyday life and allow us to reconcile with these feelings or provide us pleasure by fulfilling our desires. Our brain likely does this to maintain our mental health by providing us with scenarios of our subconscious desires and thoughts taking place to prevent these feelings from eating us up from the inside. Ultimately, I disagree with Eagleman and Vaughn’s “Defensive-Activation theory” due to the several flaws within the theory.
“A New Theory of Dreaming” by Neuroskeptic proposes a theory in response to the renowned question: why do we dream ? Scientists Eagleman and Vaughn theorize dreams ensure that our brain’s visual cortex is stimulated during its sleep. According to the theory when our visual systems are deprived of input the visual cortex located in the brain's occipital lobe degrades. Our visual cortex when deprived of visual input can start to respond to non-visual signals. For example, in blind people have an intense reaction to touch due to their occipital lobe being under-utilzed. Furthermore, the occipital lobe starts giving strong responses to touch instead of visual information due to the elongated period of time without any visual input. This rewiring in under-utilized areas in the brain is a form of neuroplasticity. Overall, the theory’s main point is that dreams are used for our brains to defend the integrity of our visual system to keep it active. Unfortunately, Eagleman and Vaughn do not provide direct evidence of dreams being used as defense. They openly admitted to the lack of factual information by saying "The present hypothesis could be tested more thoroughly with direct measures of cortical plasticity". It should also be noted that the scientists show a correlation between the amount of REM sleep and the pace of development among primate species. With this information they are trying to convey that faster development means slower neuroplasticity which in turn means there is less of a reason to protect the visual cortex. Lastly, I wanted to address how interesting this passage and hope soon enough the hypothesis proposed in the article can be properly tested to either prove or disprove the new theory.
This week I read “How the zebrafish got its stripes”. This article talked about the skin pigmentation cells in a zebrafish can be mutated to create different patterns on the fish. The zebrafish are very helpful for human research because their genetics and major organs are very similar to those of humans. By understanding the arrangement of pigment cells on zebrafish, we may be able to understand diseases caused by cell arrangement. These different pigment cells act without any central control but they still manage to create the stripe pattern on the fish according to Dr. Kit Yates. The stripes signify a key developmental process that can help humans further understand how these cells arrange themselves while in the embryos. This article interested me because it shows how just a small mutation can cause such a drastic change in appearance. Now that I know that zebrafish are similar to humans in their genetic makeup, it will interesting to see if these studies can be applied to humans on a widespread basis. I wonder what kind of factors impact the likeliness of a mutation or if they are just random.
After reading “How the zebra fish got its stripes”, I now know so much more about the process of how cells affect the pattern on animals. This research can help scientists studying medicine, find more information about certain diseases. Zebrafish might not in common with mammals but they have many genetic similarities to humans. Stripes on a zebra fish are called chromatophores which are pigment containing cells. There are three different types of chromatophore in the fish. The cells move around on the animal's surface and interact with one other and organize into their stripy pattern. Mutations can appear which can change how cells interact with each other and cause a different pattern on the fish. Mathematicians have been trying to figure out how zebrafish stripes form for many years. Scientist Jennifer Owen said that “it can help to predict the developmental defects of some less understood mutants.” Overall, scientists are discovering more information about how cells form the pattern on zebrafish which can help relate to cells in humans.
In the article, “How the zebrafish got its stripes,” I got a deeper understanding of the pigmentation of zebrafish. There were researchers at the University Bath who created a mathematical model to explain the method that the zebrafish uses to develop stripes. Most animals develop their skin pigments in the embryonic stage. Zebrafish are also popular because their genetic makeup is greatly similar to that of humans. Their biology allows for a better understanding of organ development and a better understanding of diseases caused by malfunctions in cell development. The zebrafish’s pigment cells work individually from one another and organize themselves into patterns. Creating an accurate model of their arrangement methods allows for a better understanding of how cells coordinate with each other when developing. Zebrafish pigment cells are called chromatophores and there are three types of them, which can interact with each other to produce the striped patterns as well as mutate to organize different patterns. University Bath was able to produce an accurate model of these three types of pigment cells to predict the patterns on wild and mutant zebrafish.
In the article, “Fish eggs can hatch after being eaten and pooped out by ducks,” I learned that some fish eggs have the possibility of surviving being eaten and then excreted. It was at first believed that eggs couldn’t survive being ingested by birds but after some lab tests, it was proven otherwise. A lab experimented on mallard ducks by feeding them invasive carp eggs, which was later excreted by the bird. Some of the eggs had survived being ingested, which gave a possible explanation to how species of fish could’ve been spread. Even though only a small percent of the eggs survived, the sheer amount of birds excreting them during their migratory travel could allow for a greater spread in invasive fish species.
Today I read, "Fish eggs can hatch after being eaten and pooped out by ducks." This article at first drew out my curiosity and after reading it, it was very informative. Apparently the discovery of fish eggs are able to survive after being ripped apart and eaten by ducks. When ducks poop, the eggs are still in the excrement and can later survive when it underwater. Very minimal fish are actually killed in this process.
I found the article “A New Theory of Dreaming” to be interesting. It started off by asking a question of why do we dream. David M. Eagleman and Don A. Vaughn came up with a theory that we have dreams to make sure our brains visual cortex is still stimulating while we are sleeping. The one thing they point out in their theory is that when we’re in the dark we can’t see so in theory our visual cortex takes over our other senses. The article also included that if someone has a slower neuroplasticity it means the visual cortex needs to be less protected. The article really helped me clarify as to why we have dreams and when we don't.
I read the article “Fish Eggs can hatch after been eaten and pooped out by ducks” by Carolyn Wilke. I found this article quite interesting and was drawn to it by the intriguing title. After reading this article I was surprised, as it had me thinking about all of the more unconventional ways that an invasive species could be introduced to an ecosystem. Although the amount of eggs that survived the duck’s gut was low, as stated in the article, these numbers could slowly start to add up and could create a real problem by introducing new species‘ to new ecosystems.
Within the article “How the Zebrafish got its stripes” the University Bath has started employing a mathematical model to show how Zebrafish get their striped design. This captivating handle is being studied by both formative researchers and mathematicians to make this scientific demonstrate. Researchers have found that the arrangement of this design happens amid the embryonic organize through skin color cells. They have found that the Zebrafish have a parcel of physical characteristics that are comparative to warm blooded creatures, particularly comparable organs. Due to the comparative organ improvement researchers are looking into the design arrangements in connection to medicine. By knowing how the pattern shapes in Zebrafish, researchers can have distant better;a much better;a higher;a stronger;an improved">an improved understanding of infections within the organs that are caused by the disturbed cell courses of action. By and large the College Shower is interested by the marvel in which person cells of the Zebrafish associated and organize the striped design without a central control
In the article, "How the Zebrafish got their stripes" the university of Bath used a mathematical model to represent the Zebrafish design. It was a very interesting article and I learned in how much effort was put into the process of finding fish. Zebrafish have skin color cells. With the knowledge on how zebrafish got their stripes, scientists can now tell how infectious diseases occur in them.
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