- Ongoing debate about the earliest animals: Were they similar to modern sponges or closer to comb jellies?
- Cool/creepy video about parasites
- New research indicates that the human microbiome produces a large number of novel, small proteins. These proteins may have a large effect on our health.
Monday, August 12, 2019
Summer Assignment 8.12.19
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To me, evolution is the meatiest topic of Biology. Not only can it explain where humans came from, but also the inception of the entire animal kingdom. This New York Times article explains a relevant ongoing debate about the first animals. In a heated battle, scientists are determined to prove whether the first animal ancestors resemble poriferans or ctenophores. On one side of the warzone are researchers vouching for poriferans, which are sponges. When I think of sponges I picture Spongebob. However, real-life sponges do not have the mobility and intelligence of Mr. Squarepants. Poriferans can barely move and lack a nervous system and digestive system. This rudimentary and incomplex structure leads many to believe that sponges were the first animals and that subsequent life evolved from them. This argument is convincing because it makes sense that the first creatures would have a basic structure.
Yet, the scientists of the rival party beg to disagree, nominating the ctenophores, or comb jellies, as the first animals. Comb jellies are the largest organisms to move with cilia, the hairlike protrusions that vibrate to create motion. Gene sequencing and phylogenetic analyses point to ctenophores as the first animal to evolve. However, despite the genetic evidence supporting comb jellies, many scientists, including the 81-year-old Dr. Nielson, continue to vouch for sponges as the first animal. The biggest question is if the comb jellies did come first and sponges came after, then why did sponges evolve to lose a nervous system, the ability to move, and other complex structure found in ctenophores? In my opinion, sponges were probably the first animals because of their basic structures and functions when compared to the comb jellies. Overall, no matter what the first animals are found out to be, I think it is awesome to see scientists debating with such fervency.
This week I have decided to read the articles titled, “Human microbiome churns out thousands of tiny novel proteins,” and, “Which Came First, the Sponge or the Comb Jelly?” I found the first article interesting as it showed that scientists still have not discovered too much regarding the microbes living inside the human body. The bacteria in the body have tens of thousands of small genes that produce proteins less than fifty amino acids in length, and these genes can also be categorized into over 4,000 families/groups. However, these genes were left undiscovered presumably due to the little research done in this area. Additionally, these genes were found to have been shared by all of the bacteria living inside the human body, which I found interesting as it would most likely mean that these genes are vital to the bacteria’s survival. This discovery could open up more areas for biologists to study.
The other article I read was, “Which Came First, the Sponge or the Comb Jelly?” This article focused on a dilemma occurring within the scientific community regarding the evolutionary order between the sponge and the comb jelly. The comb jelly was found to have a nervous system as well as a more complex digestive system than the sponge, making it seem like it would have evolved second. However, there is new genetic evidence that points to the idea that comb jellies existed before sponges did, creating scientific debate in the process. Depending on if they focus on the anatomy of the organisms or the genetic differences, the earlier organism in their perspective will vary.
Although the behavior and appearance of parasites can be a difficult subject to handle, the intricate mechanisms which these organisms have evolved to infiltrate their hosts are worth the attention. In the video “Four Parasites Too Creepy to Exist”, the behaviors of four extremely successful parasites are explored. I was both horrified and amazed at the processes which these parasites use to infiltrate and command their hosts. Evolution has selected for inventive and invasive mechanisms for the success of parasites in parasitic relationships. The tongue-biting isopod is a parasite which clamps onto the “tongue”, or basihyal, of fish. The isopod begins as a male, which enters an ecosystem searching for hosts to infect. Upon locating a fish, the parasite will enter the gills to determine whether the mouth is unoccupied. If so, the isopod will clamp down on the mouth, and grow into a female organism. Additional males will remain within the gills to mate with this female. Infected hosts have difficulty breathing, due to the presence of the 3 cm long female in the mouth, and the male parasites within the gills. Although this parasite is an animal, plants can be parasites as well. One notable example is the corpse flower, which is the national flower of Indonesia. The corpse flower has no roots or stems, and rather a thin tube of cells which attaches to grapevine roots. The corpse flower funnels nutrients and water from the grape vine to itself, and lives off of the substances that pass through the roots of the host. Interestingly, the corpse flower can incorporate DNA from the grapevine into its own genome, through horizontal gene transfer. This allows the corpse flower to better infiltrate the grapevine, by using the genetic techniques of the host itself. The corpse flower is also known for the smell it emits, which is similar to rotten flesh. Why the people of Indonesia chose a parasitic flower which literally smells of death to be their national flower is beyond me. Another parasite which I found interesting was the Sacculina, a genus of barnacles which infects crabs. Young barnacles are released into the water after birth, and will then attach to the base of a crab. Within the crab, the barnacle will develop into an adult, and a blister will emerge from the exoskeleton of the crab. This blister-like sac will consist of developing eggs, and receptacles to which male barnacles can attach to mate. The most horrifying aspect of this relationship is the way that the barnacle is able to control the mind of the crab. The barnacle sac exists within the brood chamber of the crab, which is where a female crab would host its own eggs. The barnacle extends a series of tubes, known as the interna, into the body of the crab, which intercept the nervous system. The barnacle releases chemicals which activate the parental instincts of the crab, forcing it to take care of the barnacle’s eggs. If the barnacle happens to have infected a male crab, the parasite will release chemicals that block the male’s hormones, and cause it to develop female behavior and characteristics. This ensures that the crab will be best equipped to provide maternal care to the parasite. Essentially, Sacculina turns crabs into zombie mothers who are forced to care for the children of another creature, which would be an interesting plot for a horror movie. I can’t help but imagine what it would be like if parasites similar to those in the video could infect humans. Needless to say, the mental image of a bug permanently attached to my tongue is not pleasant.
This week, I wanted to change the weekly reading of articles, and watch the video on parasitism. This video was especially intriguing due to the description of a cool and creepy video, and also the connection I felt with symbiosis and this video. Symbiosis is a concept we learned in honors biology, and it was based on the relationship of organisms, whether it be commensalism or parasitism. As we learned, parasites harm the host in such a relationship, and this video incorporated our previous knowledge and provided he audience with some cool and scary creatures. One of the parasites that they mentioned in the video is the tongue biting isopod, which settles in a fish’s gills, and then move in to bite down on the fish’s tongue. From there, the isopod sucks nutrients from the fish’s bloodstream, and other male isopods stay in the gills so they can mate. This negatively affects the fish’s breathing, rather than the eating habits as expected. This is because the female isopod takes up a decent amount of the volume of the fish’s mouth, and he male isopods in the gills deplete the fish’s ability to easily breathe. Withal, some parasites also use host manipulation, such as some in crabs, who manipulate the nerves of a crab so it takes care of the parasites which is harming the body. When the barnacles (parasites in the crab) reproduce, the crabs nutrients are taken by the offspring, and released for other unfortunate crabs. These are just two examples of the gruesome parasites mentioned in the video, which is a great visualization for how harmful this symbiotic relationship can turn out to be.
For this week, I decided to watch the video on parasites by SciShow. Reading articles every week became stale and dull to me and the broad topic of parasites has always been of interest. This is because of the symbiotic relationship that takes part in (parasitism), where the parasite benefits where the host is harmed. Mutualism and Commensalism have either party either benefit or one is neither harmed or hurt. At the start of the video, the always loveable Hank Green talks about the "Tongue-Biting Isopods" that inhabit fish. These parasites enter through the gills of a fish, and if there aren't any isopods inhabiting the mouth, they would latch onto its mouth. That male isopod would suck nutrients from the fish in order to grow into a much larger adult female. Of course, this would result in fish being inhabited to exhibit smaller and unhealthy features. Although the isopod has an effect on the fish's health, the reason why they appear as such is due to the isopod prevent the fish from breathing normally. Hank explains that the isopod may gro to 3 cm in length. And by looking at the fish, that is a pretty good portion of their mouth. The second parasite talked about in the video is Ribeiroia, which infects frogs. They start off as eggs in bird feces. If they land in water, those eggs would hatch and the larvae would find snails as sites to asexually reproduce. These then would find tadpoles to infect, targeting areas of development. As the tadpole grows into a frog, the parasite causes the frog to grow extra limbs. This would likely hinder the infected frogs and would result in them to be eaten by birds or other predators, restarting the cycle again. The last parasite talked about in the video was the one that really interested me. The Rafflesia "flower" is an interesting parasite as a whole due to the fact it doesn't look like one and how it works. The Rafflesia infects grapevines due to their high water content. There isn't a chlorophyll present so they wouldn't be able to perform photosynthesis. This makes the Rafflesia have to be a parasite to gain the required nutrients to survive. It also has another interesting function in that it steals the DNA of the grapevine it infects. Scientists theorize that they do this to make the vine more easy to leech offer of. And to reproduce, it gives off a smell similar to rotten flesh which then attracts flies to fly by. Pollen would stick onto the flies as they fly away, spreading and reproducing. As a whole, I learned that parasites can have special and strange properties to them that makes their job more efficient while keeping the host alive. Knowing that about 33%-50% of all life are parasites opens a new door to the possibilities of how we could manipulate these parasites to do good in the future.
For this week, the video “4 parasites too creepy to exist” caught my attention. The video, as the title alludes to, talked about 4 parasites and how they affect their host. The parasite that intrigued me the most was the parasitic barnacles that “take over a crab’s body and force it to serve them”. They do this by burrowing in crustaceans such as crabs and grow into their adult form. Then a sac shaped barnacle called the externa emerges on the crab's exoskeleton as a place for the parasite’s ovary and eggs and then the interna is developed so that the barnacle “babies” get their nutrients from the crab. Afterwards, the crab takes care of these eggs as their own since the eggs reside in the crab's brood chamber, where the crabs own babies are supposed to be, and the interna roots go into the crab's nervous system to evoke the crab's parental qualities in order to take care of the parasitic babies. The part about the parasitic barnacles that sparked some thought was when the video said: “The barnacle also interrupts the crab’s moulting cycle, probably to prevent the parasite from falling off during a shed”. I immediately thought of this a byproduct of natural selection as the previous parasites which fell off during the crabs moulting cycle probably died and did not get the chance to reproduce, whereas the ones which stayed on the crab after the cycle was able to reproduce and in turn improve the parasites gene pool. In addition, the beginning of the video states that “Scientists have estimated that anywhere between ⅓ and 1⁄2 of all life on Earth is parasitic”. The fact that this is an estimate shows how there still are parasites that we still have not had the chance to discover and study and how well parasites can reproduce and spread throughout Earth’s ecosystems.
This week, I chose to read the article “A Battle Is Raging in the Tree of Life” by Cara Giaimo. The title of the article immediately interested me because I have always been fascinated by evolutionary biology. Throughout time, scientists have studied evolution and have made so many ground-breaking discoveries. It is astonishing that scientists still have not decided on what the first-ever animal was. According to the taxonomic system, kingdom Animalia (animals) contains multicellular organisms, in which cells have nuclei and the organisms are heterotrophs. Scientists are still debating on whether the first animals were Poriferans or Ctenophores. Poriferans are sponges that are made up of pores and channels that allow water to filter and circulate through them. They contain a jelly-like mesophyll that are located in between two thin layers of cells. Poriferans can reproduce both sexually and asexually. They reproduce sexually when the male releases a sperm into the water, which travels to the female so the female sponge is fertilized, and then a larva is released into the water. The Poriferans can reproduce asexually through budding. Some scientists believe that the Poriferans were the first animal because of their lack of a nervous and digestive system. They do not move quickly, and they only consume small particles. This lack of characteristics leads scientists to believe that future organisms developed more enhanced and complex characteristics, such as a nervous and digestive system. The growth of these complex characteristics in future organisms would prove evolution has occurred, in which Poriferans were the first-ever animals. But other scientists disagree. Some believe that Ctenophores are the first animals. Ctenophores are invertebrate comb jellies that inhabit marine waters all over the world. These animals are known to be the largest animals to swim with the help of cilia. They contain a nervous system, and are capable of eating krill, amphipods, and even each other. The controversy regarding the lack of a nervous system in Poriferans, is that the Ctenophores had a nervous system. If Poriferans developed after Ctenophores, why did they give up their nervous system? This question still lurks in the minds of scientists all over the world, and will continue to be a main topic of controversy until this biological mystery is solved. What was the first-ever animal? I would be interested to find out, along with the rest of the world.
This week, I chose to watch “4 Parasites Too Creepy to Exist” by SciSchow because of my prior knowledge of parasites from biology last year. Parasitism is one form of symbiosis in which a parasite gains resources and benefits from a host, while almost always the host is negatively affected. The first parasite discussed in this video is the Tongue-biting Isopods. This parasite is a type of crustacean that lives within the mouth of a fish after latching onto basihyal (tongue like structure). They are part of the Cymothoa which often target the fish’s mouth. However, at the same time the mouth of a fish obviously has limited space. Because of this free-swimming male larva will make its way into a fish’s gills. If there is space, then the parasite will attach to its basihyal. It will then continue growing into a larger female tongue-biting ispod and will survive off the fish. If the mouth is occupied then the parasite will remain in the fish’s gills, holding up to 5 male parasites. A nickname for this parasite is also the snapper-choking isopods. This is because scientists suspect that the large female in the mouth and smaller males in the gills affect the flow of water to the gills, thus affecting its breathing. This then leads to the fish be smaller than average. This was interesting because I would have thought that the fish would have had trouble eating due to the large isopod in its mouth, yet studies have showed otherwise. The others parasite that I will be talking about is the parasitic barnacle which is a great example of host manipulation. Their life starts after birth as larvae and later on search for somewhere to settle, a host body. A suitable host may be crustaceans like crabs. After finding one, they burrow inside the exoskeleton and grow to an adult form, creating a barnacle body that leaks out of the crab’s exoskeleton. This is called the external and acts as a chamber meant for the ovary and developing eggs. The external is attached to the interna which is made up of a root-structure. The externa is what acquires food for the eggs. The female larvae has receptacles on the outside which are meant for the attachment of a male which leads to them being able to reproduce. The crab could very well destroy the parasite, yet the parasite manipulates and deceives the crab into protecting it. This is done as the parasite settles within the same place the crab would keep its own eggs (brood chamber), making it think of it as its own. The externa’s root system also makes the crab have parental tendencies by connecting to its nervous system and sending it specific chemicals. The barnacle also interrupts various parts of the parasites processes and activities. Something that was very interesting is that if the host is male, the barnacle will make it have more maternal tendencies! This is really fascinating to me. Through The year I’ve learned about different parasites. But I really liked learning about how the parasite barnacle is able to manipulate the crab into protecting it, as the barnacle is negatively affecting the crab.
For this week’s assignment I was most interested in the video: 4 Parasites Too Creepy To Exist. I learned so many different types of parasites, and how they affect living creatures. It’s pretty interesting to see how much parasites can do. One parasite that was talked about in the video were Tongue-Eating Isopods . This parasite attaches to a fish’s tongue and lives in its mouth. What I found pretty fascinating about this parasite is that it starts off as a male when it enters into the fish’s gills. When it grows up, it changes to a female. Usually fish with infections end up having “1 female in its mouth and as many as 5 males in its gills.” Scientists thought that these fish would have eating problems, but no. They believe the fish have breathing problems. The female can grow up to 3 centimeters in the fish’s mouth. Another parasite that was mentioned in the video was frog-mutating worms. This parasite can make amphibians have deformed legs, extra legs, legs not formed properly, and even missing legs. This parasite starts from bird waste. When it goes in the water, the eggs are hatched. From there the larvae infect the snails. When these infected snails reproduce asexually, they create hundreds more. Then these worms come swimming out of the sail to find a tadpole or a baby looking salamander. Then these worms infect the skin that is near the developing limb buds. Frogs grow legs as they grow up, but if they are infected with the parasites it can make the legs come out weird of these amphibians. Another parasite that I found extremely interesting was from the flower Rafflesia. This parasite is called the Giant Corpse Flower. This parasite makes this flower smell strongly of rotten flesh. This is how they get the name Corpse Flower. Beneath the flower there are no stem, roots, or leaves. Instead they have a slim strand cell that infiltrates the body of a grapevine. This flower steals the nutrients from the vine, and uses them to grow bigger, and look beautiful. Also this flower has no chloroplasts, so that it can’t photosynthesize—which makes it an obligate parasite, this means it can’t survive without a host. Just like other plants, something it has in common is that it spreads by pollination. The strong smell of these flowers attracts carrion flies. They come looking for meat, and then leave covered in corpse flower pollen. Not only does this parasite steal nutrients from the grapevine, but it also steals DNA. As it is mentioned in the video, “Researchers found that a significant portion of the corpse flower’s DNA has been swiped from grapevines.” This is known as a form of horizontal gene transfer. Its’ “genes hop between two distantly related species instead of being inherited in the usual way.” Although scientists aren’t completely sure why the corpse flower steals DNA, they suspect that “it might allow the flower to better infiltrate and manipulate the host.” From these parasites I was most interested in the Giant Corpse Flower. The part that I found most interesting was that it steals DNA. I found that to be extremely cool, because I never thought that any living creature can have its DNA stolen. Even though parasites do extremely abnormal things to living organisms, it’s intriguing how much these parasites can affect nature.
This week I watched the video, 4 Parasites Too Creepy to Exist, hosted by Hank Green and SciShow . The video begins by defining the term, "parasite" as an organism that survives by taking resources from another (host). It is a harmful relationship, especially to the host. The first parasite Hank presents is called a "cymothoid," also known as a "tongue-biting isopod." This parasite attaches itself onto a fish's tongue feeding off of its nutritious fluids circulating around the body; usually they affect skin, muscles, gills, etc. This parasite begins its journey as young male but then grows larger (in the fish's basihyal) and develops into a female. An infected fish can have anywhere between 1 female isopod latched on the mouth, and as many as 5 males in the gills. The parasites' occupancy in the fish ensues numerous side effects: an inability to breathe as well as other sicknesses. The next parasite discussed are "frog-mutating worms" or also called "trematodes" or "Ribeiroia." They have different stages in their lives involving three hosts. First, they are eggs in the waste of animals, which travel into the ocean to reproduce asexually (in huge quantities) in other organisms like snails. These worms then infect the skin of tadpoles or even young salamanders, often near developing limbs. This causes deformities in the infected organism, most probably in the legs. The final stage of the parasite's life occurs in a bird or mammal's body. In order for that to happen, they must be eaten. They use a tactic called "host manipulation." The next parasites are called "parasitic barnacles," or "Rhizocephala." They seek out bodies to prey on, such as crabs. They burrow inside the host and develop into an adult, eventually popping out of the exoskelton of the host (known as the externa). The parasite reproduces using the externa, as a place for the male to send its sperm through. The externa and the parasite all occupy the crab's brood chamber, which is where normally the crab's eggs are carried. The parasite is mimicking the eggs the crab would normally have carried. The crab is tricked into taking care of the parasitic barnacles. The final parasite is a "giant corpse flower," or "Rafflesia." The flower has no root, stem, or leaves, and often smells like rotten flesh. A strand of cells from the flower infiltrates a grape vine and steals nutrients from it. This plant cannot photosynthesize at all due to lack of chloroplasts. However, the flower does pollinate by tricking carrion flies into indirectly doing it for them. The parasite also steals DNA from the grapevine, known as horizontal gene transfer. This supposedly allows better host manipulation. Overall, this video was very informative and interesting to watch.
The human body contains a microbiome. This is our bodies internal environment, it contains thousands of bacteria and chemicals that help us survive. Think of it like a tiny biome, inside of a human. In order for the body and the immune system to function together, chemical processes need to be carried out. In the article, “Human micorbiome churns out thousands of tiny novel proteins,” it discusses scientists recent discovery in the human microbiome. The human microbiome creates thousands of proteins. These proteins fold into different shapes that can be classified as biological building blocks. Recreation of these proteins in labs can change scientists understanding and the creation of drugs for the human body.
I read the article “A Battle is Raging in the Tree of Life” this week and found it very interesting. For years, sponges (poriferans), and comb jellies (ctenophores), have been “battling” over the spot of the “closest living analogue of the first-ever animal” according to science journals. For a long time, researchers have settled with sponges being the closest relatives to the first animals, but further analysis has shown that comb jellies may be those relatives instead. The correct answer is still inconclusive as studies showed support for both the sponge, and comb jelly theories. Dr. Claus Nielsen of the Natural History Museum of Denmark believes that sponges were the first to branch off. He states that sponges don’t move quickly, only eat small particles, and don’t have digestive or nervous systems, so later organisms would evolve to gain more complexity. He says that comb jellies are already complex, having nervous systems, and the ability to consume larger organisms like krill, so if they evolved first and sponges came after, sponges would’ve had to abandon that complexity. Dr. Nielsen believes that it doesn’t make sense for sponges to have to give up the superior abilities of the comb jellies when evolving. On the other hand, Dr. Joseph Ryan of the University of Florida disagrees with Dr. Nielsen and thinks comb jellies came first. Dr. Ryan states that since organisms are constantly evolving, it’s not unusual for organisms to lose traits in the process. Dr. Nielsen replied to Dr. Ryan saying that once again, the loss of traits from comb jelly to sponge goes against natural selection and doesn’t make any sense. I personally agree with Dr. Nielsen. It makes more sense for comb jellies to gain complexity when evolving from a mostly stationary organism, like a sponge, then for sponges to go against natural selection and devolve from comb jellies, organisms possessing advanced traits, such as a nervous system.
Recent research has found the synthesis of small proteins in the gut of humans. Because these proteins are small, relatively fifty amino acids in length, they have been unnoticed when studying the microbiome of humans. Stanford University School of Medicine, however, discovered the synthesis of a plethora of proteins from various bacterial strains in the human gut microbiome. Despite the negative connotation of bacteria in contemporary society, the bacteria in the human gut aid in digestion and supplement diets. Consequently, the bacteria that humans host in their gut play an essential role in maintaining health for humans ultimately highlighting the importance of the small proteins these bacteria produce and their function. In order to find the specific protein-coding DNA sequences of bacteria, scientists at Stanford University School of Medicine compared potential sequences to larger data sets of sequences. Surprisingly, the results showed the various bacteria in the human gut have expressed genes that encode for small proteins present in the gut.
I was most surprised by the video about the 4 parasites that is too creepy to exist. When I saw the title of the video, I was hesitant to watch it because I didn’t know what to expect from the video. Based on my prior knowledge I know that parasites live in their hosts and usually harm the host they occupy. Some common parasites are ticks, tapeworms, and fleas. These take in the nutrients from humans from their blood and lead to many negative impacts. In the video, I learned about the most creepy parasites that ever existed, and I was completely surprised. The parasites are the “tongue-eating isopods”, the “frog mutating worms”, the “parasitic barnacle”, and the “giant corpse flower”. The “tongue biting isopods” attack the fish in the mouth. They start out in the water until they find a fish and live in its gills. They go and bite in its tongue, and it grows into an adult female in the tongue. It grows by taking in the nutrients from the fish’s bloodstream. Males can come in and mate with the females. The fish that are infected are negatively affected. They appear smaller and scientists believe they have trouble breathing since the tongue-eating isopods can grow up to 3 cm. Additionally, the “frog mutating worms” affects the frogs’ growth and development leading for them to have an extra leg or not have any legs at all. They start out as eggs in the poop of a bird which ends up in the water. The eggs hatch and they infect snails which produce more worms. These worms swim around and find a tadpole in the water. So, since these tadpoles are being infected, the growth and development into an adult frog would be affected. Therefore, this leads to the many leg deformities in frogs. The worms end up with birds by making their host become prey easily. Furthermore, the “parasitic barnacles” are barnacles who look for their hosts in crabs. They grow into their adult form in the crab, and they get nutrients from it. However, the crab does not get rid of the parasite because it decides to take care of it. This occurs because the parasite occupies the area of the crab where it carries its eggs. It also affects the nervous system to make the crab treat the parasite like its own eggs. Finally, the “giant corpse flower” is the one of the largest parasites and flowers in the world. They smell like rotten flesh, and they bud on grape vine. It steals the nutrients from the vine to allow it to grow larger. It also cannot photosynthesize which means they cannot make food on their own. Therefore, they rely completely on its hosts, and they also can manipulate its hosts by stealing its DNA. The parasite that I found the most creepy was the “parasitic barnacle” because it can completely manipulate the crab to do anything by protecting and taking care of the barnacle like its own. Additionally, it can even make a male crab become more female so they can take care of them. It is really cool that these kinds of organisms exist on Earth even though they are harmful and have detrimental effects.
This week I read the article “A Battle is Raging in the Tree of Life.” In this article the debate over whether poriferans (sponges) or ctenophores (comb jellies) are the closest living analogue to the first animal. Dr. Claus Nielsen of the Natural History Museum in Denmark argues for the poriferans. He believes that it makes more sense if first sponges existed then evolved the complex nervous and digestive systems found in the jellies. Nielsen argues that nature wouldn’t evolve in a way that got rid of the ability to digest larger organisms. Dr. Joseph Ryan however argues that ctenophores came first. He says that it’s not unusual for organisms to lose traits, even thought they might be superior, during evolution. The debate brings up many other topics of discussion. For example, did the nervous system, that is responsible for consciousness, evolve over again. This theory is plausible under Ryan’s side of the original debate. However, I agree with Dr. Nielsen. It makes more sense that evolution would push organisms forward and more complex rather than working backwards.
This week, I watched the video “4 Parasites Too Creepy to Exist.” When I think of parasites, the first thing that comes to mind is worms. These seem to be the parasites I hear about the most, so it was interesting to learn about a parasite in the form of a crustacean and even a flower. This video was also a sort of eye-opener to yet another side affect of the damage humans are doing to the world. The frog-mutating worms spoken in the video were more plentiful in habitats that had been touched by human hands, in the form of a dam in this specific study. I found this upsetting, and it also surprised me because I have never thought of the way a man-made dam could alter the lives of the animals living in the water the dam is holding in.
The parasitic barnacles were particularly interesting in how they change the way the host crabs bodies work. A barnacles accesses the crab’s nervous system and forces the crabs to take care of it. The barnacles also leave the crab sterilized, interrupt the molting cycle in which the crab sheds its shell, and as well as mess with the hormones of male crabs to make them seem more female.
The corpse flower is something I never would have expected to be any sort of parasite. I never realized that parasites could affect plants. The flower grows on grapevines, stealing their nutrients and even their DNA.
This week I watched the video called "4 Parasites Too Creepy to Exist." This video talks about different parasites that exist even though us humans would think they do not. A parasite is "an organism that makes its living by taking resources from another, called the host." The video talked about many parasites that were found in frogs, snails, and crabs. However, the parasite that I found the most interesting is the one in fishes called "tongue-biting isopods." This parasite belongs to a group called crustaceans called cymothoids. "These crustaceans start as male larvae and find a fish where it can settle in its gills." The parasite then moves to the mouth and bites on it to take over and grow up 3 centimeters to become a larger adult female. The tongue-biting isopod will live its life in the fish's mouth and sucking nutrients from the fish's bloodstream. Some side effects that fishes encounter with this parasite taking over their mouth are they are much smaller and less healthy because the parasite blocks the flow of water to the gills making it more robust for the fishes to breathe. This is because there is one female parasite in the mouth and almost five male parasites in the gills.
I have interests in microbiology, so the article “Human Microbiome Churns Out Thousands of Tiny Novel Proteins” really caught my attention. We know that our bodies are inhabited by a multitude of different microscopic creatures, which might sound creepy at first, but most are either neutral or beneficial in some way. For example, upon further research I learned that some of the bacteria that are living in our gut help us metabolize and can even protect our intestines against harmful diseases. Scientists from the Stanford University School of Medicine sought to see how these bacterial lifeforms operate the way they do, and found an interesting discovery. The team of researches found that there were a mass of extremely small and uniquely shaped proteins synthesized by the bacterial hitchhikers, and hypothesized that these very proteins were the working force of the gut bacteria as they could easily maneuver into and out of cells, which is needed to perform the various activities that bacteria do. However, it was unimaginably difficult to determine the DNA sequence of the genes that encode for these proteins, which is a very vital piece of information. Scientists Ami Bhatt and Hila Sberro compared the number of gene codes in each sample of a large number of subjects. The pair found tens of thousands of gene matches, which was a huge surprise when looking back at their hypothesis of there being only a couple hundred. Knowing this information, we can improve on our medicines and antibiotics. Overusing antibiotics could kill the good bacteria in the human gut, which would wreck our health even more. We could potentially develop antibiotics that avoided the proteins that the good bacteria produce, while simultaneously targeting those synthesized by the harmful ones. All in all, analyzing microbiology, especially those that inhabit our own bodies, is a crucial science that could help us further our medicinal progress, as seen in this article.
This week I have decided to read the article "A Battle Is Raging in the Tree of Life". Here it discusses the never ending conversation on what was the closest living analogue of the first ever animal. The two animals in question are sponges and comb jellies, or poriferans and ctenophores. Sponges were considered the sister group of the first animals until a genetic analysis done in 2008 stated the comb jellies were instead. This article broadcasts two point of views; one from morphologist Claus Nielsen who believes poriferans came first and the other from a student named Joseph Ryan in the University of Florida who insists ctenophores came first. Dr.Nielsen, being a zoologist since his 20s and now 80, pointed out a thought provoking point which was: “To lose the ability to digest larger organisms — to me, that is nonsense.". In other words, sponges would have had given up their nervous systems and more complex digestion if evolved after comb jellies which really does not make sense. Jospeh Ryan claims that the loss of a useful trait goes against natural selection. Until more evidence and research, scientists will not know which organism did in fact come first but, as said by Dr.Niselsen, "If you only look at the molecules and don’t think about morphology, and the function of organisms, then I would say it’s not biology any longer". This article interested me because debate in the science field is filled with information I enjoy hearing and understanding along with altering viewpoints.
A parasite is an organism that makes its living taking resources from another, called the host. Parasites give nothing back and often harm the host in the process.” - Hank Green
Nature has brought many surprises for humans to discover. An example of such a surprise is the biodiversity of the biosphere. Scientists have estimated that anywhere from ⅓-½ of all organisms on the planet are parasites! Today, I would like to talk about one of the more creepy ones, as mentioned in the video “4 Parasites Too Creepy to Exist.” While there were 4 very interesting organisms, or parasites, described in the video, I would like to talk about the one I found most interesting… er horrifying. It is the parasitic barnacle. Scientifically known as Rhizocephala, they are one of the strangest organisms known to humans. What do they do to earn such a title? They “take over a crab’s body and force it to serve them. That may sound creepy enough for you but trust me, it’s so much worse than you’re imagining.” The barnacles settle in the crab in a part called the externa. This part of the crab is where it produces sperm for females to come make offspring from. Not only this, the barnacles had settled in the brood chamber of the crab. Though the crab could easily get rid of the parasite, it doesn’t; this is because the brood chamber is where the crab keeps its babies. Furthermore, the externa of the crab is connected to the interna. This leads to the parasite having control over the crab itself. Through this, they secrete chemicals that induce the crab’s most “parental tendency.” The parasite changes the crab’s body itself, degenerating the crab’s genitalia, rendering it sterilized. This is to stop any competition for the parental care the crab is giving it. It also prevents the crab’s moulting cycle, stopping the parasite from falling off when the crab sheds. The crab is also feminized, as the parasite makes the crab give more maternal care to it. But how exactly? The male crab’s hormones change into more feminine hormones, as the females are the ones that brood the young. Finally, when the parasite is mature enough to produce more of itself, the crab flaps its abdomen, which is a motion used to help the baby crabs swim off. This, however, helps the newly made parasites go and find a new host. If this is not the most horrifying creature you’ve ever heard of, I truly don’t know what is.
This week I read the article entitled “Human microbiome churns out thousands of tiny novel proteins.” Currently, our society is focused on the environment and global warming, but biological researchers are focusing on the microenvironments present in our bodies. This research is only at its beginning stages and its practical implications have shown it will benefit people’s lives and the medical field. The precision needed to be very high for this research because of the small protein bands that were being dealt with. Despite the high possibility of error, the researchers were able to collect data, draw conclusions, relate it to other experiments, and make predictions. Surprisingly, the small proteins are easier to study and manipulate than larger proteins, which will be useful in drug development. It was interesting to learn about the little cogs, which are often overlooked, that work in the big machine that is the human body.
Nature has created some of the world’s most interesting and creepiest organisms. An example of this is parasites, which make up a third to a half of all organisms. Organisms that identify as parasites are amazing while being a bit scary at the same time. Some parasitic species such as mistletoe have become rooted in our culture, but not as scary parasites. Some parasites seem to have been taken directly from our nightmares, however. SciShow presents four different species of parasites and what makes them terrifying even though they do not hurt us.
The first parasite that Hank Green talks about is the tongue-biting isopods. These parasites swim as male larvae, searching for a fish. Once the male larvae find a fish, they settle into the gills and check if there is a female tongue-biting isopod inside the mouth. If there is not a female, they bite the basihyal on the inside of the mouth. Eventually, it grows into an adult female and continues to suck nutrients from the fish’s bloodstream. However, if there is an adult female already inside the mouth, the male larvae will settle in the gills and occasionally enter the mouth to mate with the female. The infected fish will have trouble breathing since the female isopod will take up a significant portion of the fish’s mouth and prevent water from entering the fish’s mouth and exiting through the gills.
The next parasite is the frog-mutating worms. These flat head worms start as eggs in bird or mammal excrement and hatch once they enter the water. The larvae infect snails and produce hundreds of themselves asexually. Swarms of worms will appear from snails and infect tadpoles or young salamanders. They infect near the developing limbs and get in the way of the limb’s development. The legs don’t grow correctly and when the amphibians mature, they have deformed, extra, or missing legs. Finally, the frog is eaten due to its crippling condition by a mammal or bird and the cycle continues.
A good Maryland crab is a great dinner, but the rhizocephalan barnacle has different ideas for the crab. The female barnacle larvae swim through the sea and search for crabs or other similar crustaceans. They burrow inside and develop into their adult form. A sac shaped barnacle body emerges out of the exoskeleton like a nightmarish creature from Alien. The parasite takes control of the crab and makes it protect the parasite. The host will unknowingly do its best to protect the parasite
Lastly, a famous flower that isn’t known for its smell, rather its size. The Rafflesia flowers are the largest flowers on Earth and smell like rotten flesh. They are the national flower of Indonesia and are the inspiration for the pokemon Gloom. They don’t have a stem, roots, or leaves since they get all of their nutrients from a grapevine. The flower can steal DNA from the grapevine which is called horizontal gene transfer.
This week I chose to watch the ““4 parasites too creepy to exist” video. Parasitism is the most microscopic relationship between a parasite and a host, and almost 1/3-1/2 of all life on earth consists of parasites. The most intriguing concept of this parasite-host relationship, is the affects the parasite leaves on the host both physically and mentally. For example, the tongue-biting isopod is one of many parasites, that in this case, latches onto the tongue of the fish and inhabits the fishes tongue as its own home, feeding off nutrients supplied by the fish. The overall implications of this parasite’s occupation inside the host fish results in smaller and less healthier fish. One more perfect example of a parasite- host relationship that in this case causes mutations is the frog-mutating worm (Ribeiroia) One of the biggest biological concepts studied is, mutations and biological deformities. In 2002, scientists discovered that in Northern California, many amphibious creatures like frogs, had anatomical deformities or mutations; for example, some frogs were missing legs while others had more than 4 legs. These parasites hinder proper development in organisms like frogs and overall, increase the chances of mutations spreading in the gene pool of that organism. Moreover, another very intriguing example of a parasite-host relationship, lies between a crab and a parasitic barnacle that comes from the group Rhizocephalan. This parasite is very rare in how it functions; first the parasite latches itself to the reproductive area of the crab, and from there the parasite will invade the nervous system of the crab resulting in the crab almost serving the parasite. The relationship between parasites and their hosts is very interesting topic to me because I love understanding the concept of how one organism affects the entire life of another even bigger organism.
I read the first article, "A Battle Is Raging in the Tree of Life," by The New York Times. It was an interesting article. Sponges are known to be "squishy, stationary and filled with holes," and comb jellies are known to be "soft blobs wreathed by feathery cilia." Scientists looked at present species to cast enlightenment on the originator of the animal kingdom. They saw that both organisms tell two different tales. Sponges do not pass quickly and only consume small bits, whereas comb jellies already have nervous systems, and can feed on krill, amphipods, and even each other. According to Doctor Nielsen, a morphologist affiliated with the Natural History Museum of Denmark, losing the capacity to ingest larger organisms is rubbish, although many people such as Doctor Ryan, from the University of Florida, disagree. According to Doctor Ryan, all families are continuously evolving, making the decline of attributes usual in evolution. This is very appealing because it is cool to see both sides of an argument between two scientists observing if the sponge or the comb jelly came first. It makes me wonder what really came first: the sponge or the comb jelly?
Evolution is still a topic which is still not completely comprehended. Scientists around the world are continuously attempting to develop a better understanding about our past ancestors who roamed the Earth millions of years ago. “A Battle Is Raging in the Tree of Life” was an interesting article about how scientists are debating whether the sponge or comb jelly developed first. Sponges, also known as Poriferans, are squishy and stationary organisms with holes. Comb jellies are soft blobs surrounded by cilia and are also called Ctenophores. There is a fight for the spot of being the closest living relative to the first animal. The similarities in animals stem from a common ancestor originated in the ocean at least 550 million years ago. However, scientists are still uncertain about its appearance and how it survived, so we must observe existing species in order to trace back to our origins. At first, researchers agreed that sponges gave rise to the first ever animals, but this thought was disregarded in 2008 when a genetic analysis confirmed that this title belonged to the comb jellies. Experts are currently finding evidence that supports both theories. Dr. Nielson has decided to take up the morphological aspect in this disagreement. He found out information on their anatomical and molecular characteristics and then observed two possibilities regarding the order by which they might have branched out. By doing this, he was able to determine which traits they would have gained or lost as time passed. Since sponges move slowly and only eat tiny particles, it was reasoned that they would have gradually increased in complexity by evolving parts like the digestive and nervous system. On the other hand, nervous systems were already present in comb jellies and they could eat larger organisms. If they had evolved before, it would conclude that sponges abandoned these traits. Dr. Nielsen does not think that sponges would have lost the ability to digest larger food. To me, this sounds accurate because it agrees with natural selection. Subsequent generations will get passed on traits that allow for greater survival and reproduction. But many people, including Joseph Ryan, who still refuse to believe this and who think the sponges came first say that genetic data is a more viable source to study evolutionary history. Either way, finding out about our lineages can help us fill in the missing branches of the tree of life. Scientists will gain a greater vision on the relationships between organisms and how they interact together. Discovering our past may also help us to predict our future.
This week I viewed, ‘’4 Parasites Too Creepy to exist’’. This video spoke about four parasites that are very creepy. The first parasite was a crustacean which bites on a fishes tongue, this tongue biting isopode has more larvae in the gills of the fish which blocks the breathing of a fish. The isopode grows in the fish’s mouth and has larvae. The next parasite was a species of flatworm that inhabites three different organisms in its life cycle. The flatworm was noticed when populations of fish had deformed legs due to the flatworm blocking the right way of life when a tadpole grows legs. The third parasite and in my opinion the creepiest was a species of barnacle that uses a crab as its host. I believe this was the creepiest as the way a female barnacle inhabits a crab was frightening. The barnacle grew roots in the crab and took control of all its actions making it protect the barnacles larvae, as offspring of its own. The crab would then give birth to the barnacle larvae as they are its own. The idea of an organism taking over another organisms body for solely its own benefit is frightening.
This week i saw the video i was interested about 4 parasites too creepy to exist. I find parasites very interesting and intriguing and quite annoying as well. They steal resources and kill the host during that whole process. Some parasites though uses very different tactics that others, they aren’t all the same. For example, the flower that is called Giant corpse flower or Rafflesia for it’s scientific name, detaches it’s roots to neighboring tree roots and then copies the trees DNA so as the tree absorbs water and nutrients they that the flower is part of them so they supply it with the same resources. Similar to this plant there is also the barn axle parasite that attaches to carbs thats called Sacculina, what this type of parasite does the host is similar to that of the corpse flower. First the barnacles start as regular eggs then they attach themselves too a host either a male or female and from there they grow in this sack like sand they take over the whole nervous system of the crab. They basically manipulate it and control it’s who body, making them think that they are their eggs even though they are just parasites. So instead of the crab getting rid of them, it protects them and nourishes them. And when they are ready for hatching the crabs kills itself and the eggs move on to another host.
This week, I read the article “A Battle Is Raging in the Tree of Life” by Cara Giaimo. This was very interesting to read about. It was very shocking to learn that scientists are still in a battle as to whether poriferans or ctenophores were the first ever living animals. Personally, I agreed with Dr. Claus Nielsen’s perspective because it would make more sense that if the sponges could only eat tiny particles, their genes would be passed on and develop into genes that allow the new generation of organisms, the comb jellies, to be able to eat larger particles. Even though I agree with Dr. Nielsen’s research and opinion, I found something that Dr. Antonis Rokas, a scientist with an opinion opposite of Dr. Nielsen’s, very fascinating. He said “What appear as major morphological transitions” can require “relatively simple changes in molecular terms”. He was supporting Dr. Joseph Ryan’s statement that “All lineages are continuously evolving,” so loss of traits are also common. I didn’t think that evolution can be as simple as a change in molecules. I always thought of it to be a huge process that took years and years to fully “complete”.
This week I read the article “A Battle Is Raging in the Tree of Life”. I was interested in the idea of the first common ancestor, and the disputes that scientists have on which organism came first. The fact that evolution is ever changing and scientists are always discovering new ways and species that can change the perceptions they have today on this topic. After reading the article I found both sides of the dispute to be logical. Both Dr. Nielsen and Joseph Ryan bring up important points for their side of the dispute. Dr. Nielsen believes in poriferans-first evolution, and brought up some key points, like when he stated that, “To lose the ability to digest larger organisms — to me, that is nonsense,” I found that his idea made sense to me because once the ancestors have evolved to have such important functions such as the digestive system, the descendant would not suddenly loose that ability to do something so vital. Even though there are vestigial structures in organisms, which are functions that the ancestor had that the current organism does not have, I personally don’t think that the sponge would have the comb jelly as an ancestor. To me it doesn’t make sense that the comb jelly, which after reading this article I realized that it is more evolved than the sponge to have been the ancestor of a less evolved organism. In the end after reading the article I believe that the first common ancestor is to either be the sponge, our there’s another organism that is even more simplistic than the sponge.
The "4 Parasites Too Creepy to Exist" video was very interesting. Tongue-biting Isopods were especially fascinating because I don't know of any other species that can turn from male to female. Tongue-biting Isopods do this after attach themselves inside a fish's mouth. I have also never heard of a parasite that harms its host by preventing it from breathing properly. The Frog-mutating worms were unusual as well, causing frogs to mutate sometimes missing or having extra limbs. The giant corpse flower is the first parasite I have heard of that is a plant, the well known parasite is the tapeworm. Parasitic barnacles force crabs to care for them by pretending to be the crab's offspring and can even make males more female to spark maternal care instincts. Overall, theses parasites were very interesting and new to me.
The article about the human microbiome highlighted how much we still don’t know about the human body. Even though we have a lot of intricate and advanced medical devices, there are probably still a lot of things, like those tiny proteins, that have managed to go unnoticed. With all of the shapes that proteins can take it, the possibilities could be endless. I wonder what else the researchers will learn while trying to determine the functions of the proteins. Will scientists be able to use CRISPR to synthesize their own proteins for drug development? I also really enjoyed the video about parasites this week. While watching it, I was both grossed out and amazed at the same time. The barnacles that invaded the crabs were the most intriguing parasites out of all the ones shown in the video. The ability of the barnacles to sabotage the crab’s nervous system and trick it to provide nutrients to the parasite’s eggs was pretty amazing. I’ve never seen parasites like the ones shown in the video, and I’m glad to have been able to learn a little about them. Nature will always find a way to survive even at the expense of others.
This week, I decided to read "A Battle Is Raging in the Tree of Life". I find evolution one of the most interesting subjects in biology, and though the scientific community has discovered so much, there is still a lot of gray area in the subject. One debated topic in evolution is whether poriferans (sponges) or ctenophores (comb jellies) came first. Both organisms, like all animals, are multicellular, have nuclei in their cells, and are consumers, not producers. All animals have a common ancestor, and though nobody knows what it was, scientists are trying to figure out which species was the first in the animal kingdom. Over the years, scientists have been debating if the sponge or the comb jelly came first. Dr. Claus Neilsen, a morphologist, has come up with two different scenarios. The first one is the sponges first scenario. Since sponges move slowly and can only eat small particles, this framework states that there was a slow increase in complexity in the organism. In the comb jellies scenario, since comb jellies have a nervous system and can eat larger foods, it would mean that sponges gave up all of those qualities. Dr. Neilsen says that giving up these abilities doesn't make any sense. Joseph Ryan from the University of Florida, however, disagrees. He thinks that comb jellies came first because he thinks that lineages constantly change, stating that organisms commonly lose certain traits in evolution. This, however, doesn't make much sense to me because I don't understand why sponges would evolve to lose vital characteristics like the nervous system and the ability to digest larger organisms, which leads me to believe that sponges did come first.
Knowing that there are thousands of bacteria living inside and outside the human body has always made me feel uneasy. When I think of bacteria, the first thing that comes to mind is infectious diseases. It’s difficult to comprehend that bacteria is actually necessary in aiding our body processes and good health. The article, “Human microbiome churns out thousands of tiny novel proteins,” opened my eyes to a new found existence of bacteria that produce small proteins, which can lead to monumental discoveries in the medical field. The scientist, Ami Bhatt, and her fellow colleagues began the study of these microscopic proteins. To their surprise, they found that the microbiome has actually been producing tens of thousands of these tiny proteins. Proteins assist in intercellular communication and the regulation of tissues, organs, and organ systems. The scientists predicted that these miniscule proteins could actually help keep bacteria in good health so that they can help the body fight infection. Since these proteins are so small, they are easier to manipulate, which, in turn, can help the medical field to produce new medications and find cures to complex diseases. The discovery of bacteria synthesizing small proteins is just the beginning of a larger medical breakthrough that could help people all around the world.
The first article I read this week was the article about the ongoing debate of whether the first animals evolved from sponges or comb jellies. I learned that although they are both relatively simple marine creatures, they have many differences that make it necessary to distinguish which came first. For example, sponges are porous and do not move while comb jellies have cilia to swim and look like small “blobs.” Both however are multicellular, have cells with nuclei, and consume food rather than make it just as we do today. It was commonly accepted that a simpler version of sponges today were the first animals, but in 2008 a genetic analysis undermined the long held understanding of sponges. Claus Nielsen, being a longtime zoologist, is one of the most prominent scientists researching this debate and is a supporter of the sponge-first argument. After extensive research, he developed 2 possible evolutionary paths, one where either the sponge or comb jelly came first, and predicted what traits the groups would have gained and lost. Because of our knowledge of natural selection and evolution, it is commonly believed that organisms only become more adequate for survival as their environment changes. Therefore, Nielson believes in the sponge-first argument because if comb jellies came first it would mean they had given up their nervous systems and more complex digestion. Many scientists disagree with Nielson and instead suggest that a loss of traits is common in evolution, a relatively simple process in molecular terms. Overall, this argument causes scientists and the world to question the commonly held theories of natural selection and evolution, since it is still not known whether or not an organism can lose a trait that would make survival easier. With the continued study of this topic, we can have a better understanding of the animal kingdom and evolution.
I then watched the “4 Parasites Too Creepy to Exist” video, and it was interesting to me that 1⁄3 to 1⁄2 of all life on earth is parasitic because these life forms are not greatly understood. The video covers four parasites with very strange traits that help them infect the hosts which they attack. The first parasite that was most interesting to me was the cymathoa, which first attacks a fish’s mouth and “tongue” as a young male and later develops into an adult female. After the female lives in the fish’s mouth, male parasites from the gills mate with the adult female. This was so strange because it is widely unknown about any sex-changing organisms. I also thought that the “corpse flower,” which is the largest flower in the world, was interesting because they have no leaves, stem, or chlorophyll, therefore surviving solely on the host which it attacks. They steal not just nutrients but DNA from grape vines, which is not seen in common organisms. This video made me realize how little the world knows about all the organisms and life forms on this earth and that no trait is impossible to see in an organism.
This week I was very interested by the article titled "A Battle Is Raging in the Tree of Life". It discusses how scientists are continuously debating about what the closest living organism to the first-ever animal is. This debate is currently between poriferans, also known as sponges, and ctenophores, also known as comb jellies. The article states that all animals share certain traits but nobody knows what the first animal with these traits was like. Some scientists believe that sponges are the closest to the first animal which leads to the conclusion that the first animals were simple and spongy. Others believe that comb jellies are the closest to the first animals due to a genetic analysis in 2008 that supports this theory. In the article, a morphologist named Claus Nielsen explains his view which I believe is plausible. He states that if sponges came first, other organisms would have evolved to become more complex and developed digestive and nervous systems. If comb jellies came first, organisms such as sponges would have evolved to lose digestive and nervous systems since comb jellies already have these. This seems like going backwards in terms of evolution and goes against natural selection. Dr. Joseph Ryan of the University of Florida, however, agrees with the idea that comb jellies are the closest to the first animals due to genetic data that suggests that even this seemingly impossible scenario could be possible. Dr. Nielsen believes that people must not focus on only one specific aspect that provides evidence for one theory or the other. He believes that people must look at both the molecules that make up these organisms and the evidence that is presented through morphology. Evidently, scientists on both sides of the debate present valid points. Although I agree with Dr. Nielsen's view, I am not completely dismissing the other possibilities explained by Dr. Ryan. Further research will most likely present more evidence for both theories but I think that eventually one theory will become more widely accepted than the other.
I found the article, "Human microbiome churns out thousands of tiny novel proteins" to be very interesting. As much as we know about the body and its processes, this article highlights what we don't know. Researchers discovered extremely small proteins that hadn't been seen before in any other previous study. The article discussed how important understanding these tiny proteins can be for the future of medicine, healthcare, and furthering the knowledge of the human body. Because these proteins are smaller, they are easier to study. Their small size also allows for experimenting with certain things that are more difficult with larger ones. Understanding these small proteins and. the roles they play can help us better understand how the body works and the steps needed to be performed to operate. Finding out how these proteins work, what they do and how they react with the body can also further develop and improve healthcare and medicine.
After watching the video on parasites and reading the article “Human microbiome churns out thousands of tiny novel proteins”, I learned about several parasites that I never heard of or were not so informed on and about how the human microbiome produces tens of thousands of proteins that have gone undetected from scientists for a long time. A few of the parasites I learned about were frog mutating worms, known as Ribeiroia ondatrae. These worms start off as eggs inside mammals and then end up in water via feces. Then they infect snails, asexually reproducing inside of them, and then after hundreds of them are created they find a tadpole or salamander and infect skin near developing limbs. These worms screw up the tadpole’s metamorphosis and end up adding limbs, deforming them or removing them entirely. I find it interesting that a parasite would be able to completely mutate a frog's leg and it also interests me further that this is how the life cycle of the worm progresses. Since the frog is crippled, it is easier to be caught by birds or other predators. Then the cycle repeats itself. I find it interesting that the worm is able to adapt to the bodies of several organisms and still be able to succeed.
In the second article “Human microbiome churns out thousands of tiny novel proteins”. The article says how scientists found several thousand new protein families produced within the human microbiome. I find it interesting when the article said that these proteins were “too small” to be detected by scientists. I thought that scientists were able to detect anything down to the microscopic level. In the article it says that scientists turned a blind spot to the human biome, and this would explain why they weren’t able to see the proteins, however with modern technology there’s no reason why they couldn’t have found them sooner.
This week I chose to read the article “A Battle Is Raging in the Tree of Life.” This article explains the ongoing battle of whether the sponge or comb jelly came first. Animals have certain characteristics in common such as they’re multicellular, the cells have nuclei, and they eat food rather than making it. This article shines light on how it important it is for scientists to look at existing species such as sponges and comb jellies to learn more about the ancestors of present animals. Biologists are hoping to study modern animals to answer questions like “What type of genes did the ancestor have?” and “What kinds of traits did the ancestor have?” For many years, most researchers believed that sponges were the sister group of the first animals, but that theory has been tested multiple times throughout the years. After a genetic analysis supported comb jellies being the sister group of the first animals in 2008, evidence has been found to support the comb jellies theory as other studies still support the sponges. Dr. Nielsen, a morphologist, explained his viewpoint on the battle between comb jellies and sponges. He said he thinks about how living organisms function like how they respond to certain things in the environment and how they reproduce. He analyzes information about the molecular characteristics of comb jellies and sponges to support his argument. Like Dr. Nielsen, scientists have different methods of finding evidence to find a conclusion to this never ending battle. I found this article to be very interesting as it clearly showed the importance of studying existing animals to reveal new information about the ancestors of specific species.
There is so much about evolution that we do not know, there is always more to discover about how humans have been formed by the earliest animals. It has recently been uncovered that sponges have been the earliest animal to come on earth. This raises deeper questions about how and when many of the body systems have formed and evolved. IT is also intriguing to see how we have branched out from the common ancestors 550 million years ago. Also, it raises the question that wether if us humans have lost some beneficial traits over the years.
The article “A Battle is Raging in the tree of life” is an interesting read that discusses the debate over which animal was first, sponges or comb jellies. Scientists attempt to find the founder of the animal kingdom which is unknown. It is important to keep in mind that every animal Earth has several similarities. These shared traits includes we are multicellular, each cell has a nucleus and are consumers opposite of autotrophs. This leads scientists to believe that the original animal must have had these same qualities as modern animals. The side which most people supported has shifted overtime as gene technology becomes more advanced. For instance a genetic analysis in 2008 has supported the theory that comb jellies where the original animals, although other studies have pointed otherwise. The video “4 Parasites Too Creep to Exist” detailed intriguing parasites and the way they work as well. However, I was most drawn into the parasite last on the list which was the giant corpse flower, also known as rafflesia. Before watching the video, I was not aware that this parasite actually inspired the design of a pokemon which I found to be a fun fact in the video. Furthermore, up close it somehow has the smell of a corpse. Rafflesia survives off of the nutrients of a grape vine since it is unable to survive on its own without chlorophyll to have themselves. Hank Green explains that in addition to stealing nutrients of a grape vine, it also steals the DNA in a form known as horizontal gene transfer, which makes it an unusual parasite that is a gene stealing parasite.
This week I decided to read, “A Battle is Ranging in the Tree of Life.” I was fascinated by the title beacuse I love to learn about evolution and ecology and how animals interact with their environment. I also love to read about debates and conflicting issues because these topics capture my attention. In this debate, there were two creatures that were caught up in a raging battle, which was about which creature is the closest living analogue to the first animal to exist on Earth. Porifernans are squishy and stationary sponges. Ctenophores, also called comb jellies, are soft blobs wreathed by feathery cilia. Scientists published in the “Royal Society Open Science” that sponges won the debate, though both creatures lined up pretty close. Giaimol explains that all animals, including sponges, comb jellies, and living things have some common traits: we are multicellular, we have nuclei, we have a common ancestor, and we consume food. However, there is still uncertainty in the science world of what the first animals looked like and behaved, so scientists are now digging deeper into the origins of existing species. Later on in 2008, scientists discovered, from a genetic analysis, that comb jellies were the closest ancestors, not porifernans. While multiple experts believe in the comb jellies theory, new genetic studies still point to the sponges. To clear some confusion on the issue, Dr.Nielsen, a morphologist affiliated with the Natrural History Museum, decided to take a morphological approach to the question. He combed through papers on porifernans and their relatives, and browsed through information about their molecular and anatomical structures. Then, Dr.Nielsen analyzed two possible scenarios: one in which porifernans branched out first, and one in which ctenophores did. The results showed that sponges don’t move quickly and ate tiny particles and that in the porifernans scenario, a gradual increase in complexity was involved. Comb jellies already had nervous systems, and if the ctenophores evolved first, that would mean the sponges gave those things up. Nevertheless, many people, such as Joseph Ryan, disagree with this theory and claim that ctenophores evolved first because evolutionary trees based on morphological studies are often less rigorous and objective than ones based on genetic data. Still, the battle ranges on and deeper issues rise to the surface. This controversy is still a major debate between scientists today and sparks even more interesting questions about evolution and anatomy.
The article, “A Battle Is Raging in the Tree of Life,” written by Cara Giaimo explained the ongoing debate about whether the earliest branch of the animal family tree were sponges (poriferans) or comb jellies (ctenophores). The belief was that the sister group of the first animals were sponges as they are known to be the simplest organisms. New genetic studies suggest that ctenophores could in fact be the oldest sister group to all other species of animals. If this is true, understanding about how animal life evolved should change. Phylogenetics is the study of how organisms relate to each other as they develop over time. In order to determine the earliest branch of organisms on animals’ phylogenetic tree, scientists researched the anatomical and molecular characteristics of sponges and comb jellies. Some scientists believe that sponges branched off first because they are simpler and only able to eat tiny particles. This means that they gradually increased in complexity and developed features that comb jellies have. Others suggest that the common ancestor was comb jellies. This would indicate that the common ancestor of all living animals had complex features which were lost in the evolution of organisms such as sponges. The argument against this theory is that the loss of a useful trait goes against natural selection. While this is still an ongoing controversy between scientists, the new genomic analysis has led researchers to believe that the comb jellies precede sponges, even though they’re more complex life forms. This new research could help scientists further their investigation about what the first animal looked like or how it lived by looking at existing species.
One of the most constantly changing topic in science today is evolution. Evolution is the idea that over time all organisms have adapted and changed as a direct result of the changed atmospheres and environments that they lived in. Learning more about the different characteristics of animals can often time reveal the numerous different relationships amongst different species. In the article “A Battle Is Raging in the Tree of Life” the author explains that an ongoing debate has erupted in the science field trying to understand whether the Poriferans species comes before the Ctenophores species. At the moment the sponges are the victors, however this is an idea similar to the question of whether the chicken or the egg came first. It is likely that yet another discovery will be made changing what is currently true. In order to properly compare species, such as the sponge and comb jellies, scientists have to look at current species. They compare modern species to understand what their ancestors were like. This can reveal information such as how complex the organism was, or what genes and traits it pertained. While initially it was believed that sponges were the ancestors to the comb jellies, this thought was then proven wrong when in 2008 all signs were pointed towards comb jellies. Yet some genetic studies still prove sponges to be the ancestors. Scientists have gone back and forth with this concept, using all methods to understand the history behind the animals. It is crucial to understand where one came from in order to completely understand oneself, causing evolution to be an important study in science today.
I’ve always loved the topic of evolution. I found it really interesting and I loved learning about it last year. When I saw that there is an article that has to do with evolution, I immediately wanted to read it. I found it really interesting. It is about which organism we descended from. Some biologists believe that it was a poriferan, which is known as a sponge and others thought it was a ctenophore, also known as the comb jelly. For many years researchers have been disagreeing about which organism we ascended from. It’s a very interesting topic, how can so many traits change over a period of time. One species can be a totally different species due to evolution and natural or artificial selection. Animals are all multicellular, we consume food, and we have a nuclei in our cells. Those traits were shared with our common ancestor that lived over 550 years ago. However, no one knows what the first animal looked like and so scientists study species that live today to find out what animal our ancestor was. Scientists ask questions that they want to know about that animal, such as what genes and traits did it have? Also, how complex was it? For many years scientists thought that sponges were the “sister group” of the first animals. However, later in the year 2008 a genetic analysis led some scientists to believe that it was actually comb jellies. There are some genetic studies that say it is the sponges and other support that says it’s the comb jellies. First, sponges don’t move quickly and they eat only small particles. While, comb jellies have a nervous system, and can eat krill, amphipods, and each other. This shows that if the first animal was the sponge then it would have had to greatly increase in its complexity gradually because groups that came after it had a digestive and nervous system. In the article it says that if the comb jellies came first then the sponges would have had to lose the traits that the comb jellies had. Why would an organism lose the ability to digest bigger organisms? Dr. Nielsen said that it was complete nonsense. He also said that losing a trait that is useful goes against natural selection, so it didn’t make sense how the comb jellies would have come first. This is a very complicated and interesting topic to study because no one knows the answer to which animal came first. It could definitely be a third animal that these scientists never even thought about. I really enjoyed reading this article and seeing the different views on this topic.
Life has many ways of surviving Earth's various environments, one of which, has proved to be popular among them. In the video, “Parasites Too Creepy to Exist”, the host Hank Green, details several interesting parasites and their methods of surviving. Parasites survive by taking resources from the host which they inhabit, which usually ends up harming the host organism. Green begins by describing a crustacean that lives within the mouth of a fish, the tongue-biting isopods, known to be apart of the cymothoid family. These parasites usually nest within the mouth of a fish by first beginning as male larvae that swim in the ocean, only later to enter through the gills and settle in the mouth. After attaching, the parasite grows into a larger female while sucking on the fish’s bloodstream for nutrients. The results are fish that are smaller in size and more unhealthy, which is due to the trouble it has in breathing as the size of the parasite blocks their mouth. Another parasite which causes medical complications is Ribeiroia, which infected bodies of water near Northern California, causing deformities in the legs of amphibians, such as frogs and salamanders. These parasites start off at eggs in the feces of birds, later turning into larvae and infect snails to reproduce into worms. They later travel to find tadpoles or young salamanders, which they infect the skin near developing limbs, causing deformities in limb development. Due to their deformities, it makes the frog more susceptible to being consumed by birds, only repeating the cycle of reproduction. This behaviour of making the host become more susceptible to predators is seen in snails which are infected with Leucochloridium, which make the snail more active, therefore making it more likely to be eaten. Another parasite that has perfected host manipulation is the Rhizocephalan Barnacle, which infects crabs. Baby female larvae go in search for suitable host and burrow into a crab, only to later grow a barnacle body on the exoskeleton of the crab, called the externa, which serves as a place for ovaries of the parasite and a place for male larvae to attach to. The connection of the externa to the brood chamber of the crab leads the crab to believe that the eggs are that of hers. The parasite also prevents the crab from moulting, which eliminates the chance of the parasite falling off and also transforms male crabs to act more female to enable it to care for the eggs. Rafflesia is another interesting parasite which resides on grapevines and has the foul stench of rotting flesh. Due to the grapevine containing a lot of water and other nutrients, the parasite doesn’t need to worry about producing its own food, which also means that it requires the host to survive and can’t do so without it. It reproduces by attracting flies with its smell of rotten flesh, and having then carry the pollen for distribution. This video details the extreme methods that the parasites use to survive in their environment and its effectiveness. These show how parasites have a place in every environment and their role/impact.
I read the article “A Battle Raging in the Tree of Life”. I find it surprising that, even after all this time, scientists are still debating what animal was the first or at least what animal, in present day, is the closest to what the first animal was like. However, there are valid sides to both arguments as to whether the poriferans(sponges) or the comb jellies(ctenophores) were the first animals. Dr. Nielsen, who decided to take a morphological approach to the issue, took two possibly evolutionary scenarios where either poriferans branched off first or ctenophores did. Dr. Nielsen ultimately decided that only the scenario with the poriferans makes sense, because they would have had a gradual increase in complexity, eventually evolving to gain things like digestive or nervous systems and the ability to eat large organisms. However, ctenophores already had nervous systems and could eat large organisms, meaning that they would have evolved to lose the ability to eat large organisms. The sponges, who would come later in this scenario and don’t carry these traits, would have had to give those things up. In the eyes of Dr. Ryan, however, the scenario with the ctenophores still makes sense. He argues that what may appear as “major morphological transitions” can require “relatively simple changes in molecular terms.” The loss of useful traits, to him, is common during evolution. There are two valid points to this argument, which makes further research on this topic necessary. Ultimately, neither one of these organisms could be the first animal. Who knows?
Scientists have recently been debating whether the comb jelly or sponge organism came first on the evolutionary timeline. These organisms have been researched thoroughly in order to identify the first organism alive. Despite beliefs that sponges are the sister group of the first organism, recent genetic discoveries have pointed to the comb jelly. Dr. Nelisen analyzed certain characteristics of the organisms: he concluded that the sponges were slow moving and can only eat small particles, leaving lots of room for increased anatomical complexity over time. He also determine that comb jellies already had more complex systems such as nervous systems. This lead him to conclude that the sponges came first. Gaining information about the evolutionary order would reveal whom any times the nervous system of modern organisms have evolved. The article regarding the human microbiome claims that the bacteria form many proteins previously unnoticed. Not only are these proteins currently unidentified but they also may have the potential to form unidentified biological building blocks. The amount of bacteria on humans is great, and understanding of them could cause a revolution in drug related knowledge. However, our molecular understanding of bacteria's assistance to us is not advanced. The article states that the function of the smaller proteins is to move through cell membranes and deliver messages to other bacterial cell. A genetic study revealed that the genes that composed these proteins came from thousands of different families unblocked in various biological processes. The practicality of utilizing these smaller proteins in drug study is extremely high as well as they are easier to study than proteins that are larger.
There are millions and trillions of bacteria in our bodies. These bacterias are made up of proteins that can help us improve and advance drug development. This week I read “Human Microbiome Churns out Thousands of Tiny Novel Proteins”. Stanford University School of Medicine discovered that human microbiome produce proteins that have recently been discovered. I found it shocking how the proteins belong to 4,000 new biological families. As per the researchers the proteins folded into unique shapes. Once the researchers recreate the proteins in a lab, researchers will be able to understand how microbiomes affect humans. The article than list questions that remain to be answered about the very small proteins. Due to the size of the protein it is more difficult to study and learn more about them. The proteins account for more than all cells found in the human body. The proteins have been considered a ‘blind spot’, meaning their existence has been ignored. All though these proteins are small I found it interesting how they can help with our digestion, supplement our diet, and keep us moving. Think about what we can do once we understand more about these proteins. Another article I read this week was about a debate about the earliest animals. The two groups that have been at the center of the battle, are the poriferans and the ctenophores. The poriferans are known as sponges that a squishy and stay in place. The ctenophores also known as comb jelly are soft blobs that are covered by feather cilia. As per the new analysis based on Royal Society Open Science, the sponges claim the victory of being the first create to be alive. All animals have one thing in common: we all are multicellular, have at least a nuclei, and we consume food rather then create it. In addition we all have a common ancestor, however the only problem is that we don’t know how it looks like or how it lived. I found it shocking how we still don’t know how the first animal looked like. Due to today’s technology I would think they would have been able to recreate a 3D model. The article then continued to aguare and give more facts about each organism. In my opinion I believe it was the poriferans that came first.
This week I watched the video "4 Parasites Too Creepy to Exist". As the clip explains, parasitism is a relationship between two organisms in which one benefits while the other one is harmed. I was alarmed upon learning that 1/3 to 1/2 of all life on Earth is parasitic, especially because when I hear parasite I think of something deadly and microscopic. As the narrator began to discuss tongue biting isopods, he briefly mentioned that they are part of a group of crustaceans that attack fish, called cymothoids. It made me wonder about how scientists classified the many organisms on the planet, and I became curious of what genus/ species groups exist that are so random and fascinating. This parasite hinders the breathing of several types of fish, for usually one female will thrive in the fish's mouth while five male's make home in the gills. The next parasite, Ribeiroia deforms the legs of amphibians. Effected amphibians were found more in artificially damned ponds of water than natural bodies. I found it interesting how this statistic implied that the impact humans leave on Earth effect many organisms we have never even heard of. Following, the parasite Leucochloridium inhabits snails and effect their eye function, making it easier for birds to prey on them. In a similar way to how these creatures manipulate their hosts, female Rhizocephalan barnacles settle on crustaceans. They use the nutrients of the crustacean to feed their offspring. Because the parasite emerges in the host's brood chamber, it tricks the host into keeping it alive. Finally, the flower and parasite Rafflesia surprised me with its size, for it can be more than a meter across. However, they are able to grow so large because they take nutrients from the vine beneath them. Also extremely interesting, this flower does not contain chloroplasts, and so it can't photosynthesize! To add, this flower steals DNA from the vines it takes nutrients from, which I didn't know was even possible. Essentially, parasitism has caused evolution amongst species that will continue to change as they act as hosts to parasites that evolve as well.
It is common knowledge that every species on earth shares a common ancestor. But, the debate over what is that one organism still continues to this day. In the article, “A Battle is Raging in the Tree of Life,” it is explained that scientists are fighting over which organism takes the mantle of the first organism ever: the poriferans or the ctenophores. One side believes that our first ancestor would most likely resemble poriferans, which are more commonly known as sponges, because they are stationary and have less complex structures and functions. Poriferans would fit the idea of being the first animal because of the potential to evolve to a more complex organism. But, unlike poriferans, ctenophores already had nervous systems and could consume krill, amphipode or each other. Ctenophores or comb jellies were blob-like organisms with cilia that closely resembled hair, they had a more compounded structure than sponges. It would make sense for the poriferans to come first, since there is no reason for sponges to lose the nervous system if they had evolved from the ctenophores. Nevertheless, some scientists still vouch for the ctenophores, supporting their opinion with the that dependability of genetic data that resulted from their study. They argue that the loss of trait is a common occurrence in evolution. I would easily support poriferans as the first organism for the sole fact that there is no actual reason for sponges to give up movement and a complex digestive system which they would have gained from the comb jellies. I’m entirely fascinated in finding out which one will take the title as the first organism, but more so, I want to know what more evidence that scientists can discover to support either side of this debate. It will be very interesting to see how this will end up.
I surprisingly found the video about parasites to be quite interesting, although there were parts in which I was disgusted. Especially when the narrator talked about the parasitic barnacles. My first thought when watching this video was how similar humans are to parasites. Like the narrator said, “A parasite is an organism that makes its living taking resources from another, called the host.” That is exactly what we are doing to the earth. We are constantly poaching animals, cutting trees, and destroying land to survive. But at what cost? Eventually, like all other parasites do, we will have to find a new host as our current one dies. But unlike other parasites, we presently don’t have another host available. Something I found strange in this video was the corpse flower. The narrator stated how these flowers don’t have chloroplasts, but in honors biology I learned that all plants have chloroplast in their cells. Does this make corpse flowers the exception, or are they not plants, but fungi even though they are called flowers?
Parasites are organisms that take the resources of others in order to survive. The video, “4 Parasites Too Creepy To Exist”, discusses four different parasites. The first parasite is the tongue biting isopod. The tongue biting isopod bites the tongue of a fish. It enters through the gills, checks in the tongue is available and then eventually nestles into the fishes mouth. When scientists researched this parasite, they discovered that most of the fishes they inhabit become quite unhealthy. The parasite is hindering the fishes ability to breathe. Frog mutating worms ribeiroia, also known as frog mutating worms, hinder the development of frogs. Studies show that there is a clear correlation between ribeiroia numbers and the amount of leg deformities in a pond. Scientists realized that the deformities the worms cause actually benefit it. Due to the deformities, frogs are more likely to be eaten by birds, a vital step in the worms life. Another example of a parasite is the artistic barnacle. The parasitic barnacles seek out host bodies, instead of solid surfaces. Eventually, after they have found a suitable host, a sac shaped body emerges from the body of the crab. This body, the externa, holds the ovaries of the parasite. Once babies are formed, they need to be fed. They are fed through a series of of roots, the interna, that infiltrates the body of the host. The host will not abandon the ovaries because they formed in the area where the organism would normally have its ovaries. This causes the host to have a motherly feeling towards the parasite. The parasite makes the host go through a series of changes in order to ensure its safety. Similarly, on the islands of Southeast Asia, Rafflesia, “the corpse flower”, steals nutrients from grape vines due to the grape vines ability to collect an enormous amount of water. Though the thing that surprises scientists the most is that this flowers isn’t just stealing resources, it is also stealing DNA from the vines. This is called horizontal gene transfer. Researchers believe e that the cause of this is to better manipulate the host, although the real reason may still be unclear.
This video was extremely interesting. I had never thought to learn this much about certain kinds of parasites, but this video opened up my eyes to the amount of interesting organisms out there. Although I had learned about parasites in school, I had never learned anything this in depth about parasites. I thought that out of these four, the most interesting parasite was the parasitic barnacle. I am fascinated by its complexity and the way that it changes the way that its host thinks.
This week, I read the article “Human microbiome churns out thousands of tiny novel proteins”. This article had heavily interested me as the content itself was quite astonishing and unbelievable. This article discusses the human microbiome and how the tiny creatures consist of thousands of unexpected genes. These genes create proteins that are also very miniature. These proteins are usually less than fifty amino acids in length, This truly amazing fact surprised me and made me want to research more. It was quite unexpected, that such tiny and miniature creatures could have such a significance. Additionally, studies have shown that the proteins predicted to be encoded by the genes could be sorted into more than 4,000 related groups, or families. These proteins are likely to be involved in key biological processes such as intercellular communication and warfare tasks, that are important to keep the bacteria healthy. Moving on, a bunch of collaborators are still working on figuring out the functions of these proteins. The functions of these small proteins will be helpful for future antibiotics and drugs. This human microbiome can turn into a whole different area of biology for study.
The article I chose to read this week was “A Battle Is Raging in the Tree of Life”. I chose this article because evolution was one of the chapters that made most sense to me in my Honors biology class. It was also very interesting to see how species have evolved so much in so many years. This article discussed the battle between two groups: poriferans (sponges) and ctenophores (comb jellies). For a long time scientists believed that the sponges were the first animals. But in 2008, evidence pointed to the comb jellies instead. Claus Nielsen, a morphologist, decided to investigate this question during his retirement. He said, “I think about living organisms. I think about how they function, how they react to the environment, how they eat, how they reproduce and so on”. He researched and looked through many papers on both species. He concluded with two scenarios. One scenario is that sponges move slowly and can only eat tiny particles. This means that they gradually increase in complexity. On the other hand, the second scenario is that the comb jellies already have nervous systems and can eat krill amphipods and even themselves. This means that the comb jellies could eat the sponges. So the sponges would have to give up their digestive systems. According to Dr. Nielsen, it makes no sense to give up the ability to digest larger organisms. I don’t know if I agree with him, but I definitely liked his approach towards this issue. Instead of looking at the molecules, he decided to look at the functions of the organisms. Compared to other scientists, this approach was unique and brought us something new to think about. I hope the other scientists can use this information to find the answer to this question: Are sponges or comb jellies the first animals?
This week I had read the article “A Battle Is Raging in the Tree of Life.” I had decided to read this article because evolution and prior knowledge about life had always sparked interest in me. In this specific article, scientists were arguing if either Poriferans (sponges) or the Ctenophores (comb jellies) was the closest living analogue of the first-ever animal. For many years, it was accepted that sponges was the closest living analogue of the first ever animal, but then the idea of comb jellies was brought up and kept a few people thinking. Arguments about each of their characteristics were brought up. Sponges can’t move very quickly and can only eat tiny particles whereas comb jellies already have nervous systems and are able to eat living things. With this argument, the scientists believe that sponges came first because they would have to give up these characteristics to evolve. Joseph Ryan from the University of Florida thinks Ctenophores came first because he believes that evolutionary trees based on even the most careful morphological studies are often less rigorous and objective than ones based on genetic data. The argument between which came first is an ongoing conversation and will leave many scientists wondering.
The article “A Battle Is Raging in the Tree of Life” deals with an intense ongoing debate regarding the first-ever animal. According to the text, every mammal is multicellular and we can consume our food rather than producing it. Since we are multicellular organisms, we have a mutual ancestor, either the sponges or comb jellies. The two groups, poriferans (sponges) and ctenophores (comb jellies) have been in an enraged dispute for the past decade. Poriferans are spongy and packed with holes while ctenophores are soft globs enclosed by feathery cilia. Sponges are only fit to consume small particles and aren't capable of moving quickly. On the other hand, comb jellies already have a nervous system. For several ages, experts have been using current animals to assume our ancestor’s characteristics. As a result, many researchers agreed that the sponges were the sister group of original animals until, the newer studies that steered towards the comb jellies hypothesis. As a morphologist and a zoologist, Dr. Nielsen applies his research on the two groups to conclude that the sponges were the primary creature. In contrast, other specialists such as Dr. Ryan and Dr. Rokas questions Dr. Nielsen’s views. The differences between the expert's beliefs lead to a heated argument. The two specialists believed that the loss of traits was caused by modest alterations in molecular terms. Dr. Nielsen challenges the specialists “If you only look at the molecules and don’t think about morphology, and the function of organisms, then I would say it’s not biology any longer,” he further claims that loss of trait goes against natural selection. Overall, some argue that poriferans were the earliest animal considering it involves a gradual increase in complexity while others support the idea of ctenophores as the initial mammal because of the loss of characteristics. The definition of evolution is the process by which distinct species of existing organisms are thought to have developed and diversified from more primal forms. Therefore, I believe that poriferans were the first animal since it makes sense for the organism to develop as they evolve.
I found the video about parasites very interesting. The video, “4 Parasites Too Creepy To Exist”, discusses four different parasites. The first parasite is the tongue biting isopod. This type of parasite bites the tongue of fish and eventually ends up staying in the fishes mouth. The fish observed with the parasite in their mouth usually become unhealthy due to the fact that the parasite doesn’t allow the fish to breathe. Another parasite called Ribeiroia deforms the legs of amphibians. Effected amphibians were found more in man made bodies of water than natural bodies. I found it interesting how this shows that the impact humans leave on Earth effects many more organisms than we know of. In the islands of Southeast Asia, Rafflesia, “the corpse flower”, steals nutrients from grape vines due to the grape vines ability to collect an enormous amount of water. What surprises scientists the most is that it not only takes water from the vines but also takes its DNA. This is called horizontal gene transfer. Researchers believe that the cause of this is to better manipulate the host, although the real reason is still unknown.
Today I would like to comment on the article
“Human microbiome churns out thousands of tiny novel proteins”. I picked this article because this idea seemed new and unrealistic to me and I wanted to learn more about the topic. The article discusses a recent Stanford Discovery that could advance drug development and change our view of human health. They found that the trillions of bacteria present in our body make proteins. This raises a large variety of questions such as how do they communicate and how do they protect themselves. Due to the size of the proteins however, it is very difficult to use the traditional method to study them. In stead they compared potential small protein coding genes among each different microbes. They found that 10s of 1000s of proteins were being created and they fit into 4000 groups or families. Hopefully, due to this discovery, we will be able to further human health with this discovery
This week I read the article, "Human microbiome churns out thousands of tiny novel proteins." Ami Bhatt, a scientist, and her colleagues had found that microbes inside and outside humans are making proteins. When we first think of bacteria, the first thing we all think of is germs and sickness. However, this article showed me a new perspective where Stanford researchers had found that bacteria in and on our bodies, make proteins that could help aid in human health as well as help aid in the advancement of drug development. The proteins are so small that they turn into shapes that are unidentified, however is these proteins' shapes and functions could be recreated in labs, researchers and scientists could have a better understanding of how this microbiome affects the human health's well as help with the discovery of new drugs.
After reading the articles, I had found the article " A Battle Is Raging in the Tree of Life," the most interesting. As said in this article no one is aware of the first known animal, what it looked like, and how it lived. As a result, scientist are observing today's existing species and analyzing to find commonalities with their respected ancestors ( founder of the animal kingdom). It clearly states, “By comparing modern animals, we’re trying to infer what the ancestor was like." By this they can find the genes it had and the certain traits as well. This article mainly focuses on the "battle" between if either the Ctenophores or the Poriferans were the closest living analogue of the first-ever animal. Scientists had observed the different characteristics of each to judge and come to a consensus. For example, they had discovered that sponges have the ability to move swiftly. This argument is ongoing and is still being researched by many scientists.
For this assignment, I chose to specifically focus on the article titled, “A Battle Is Raging in the Three of Life”. This article pokes at a debatable scientific question: which came first, the sponge or the comb jelly? To first think about this question, the organisms had to be introduced. Sponges, or Poriferans, are squishy, stationary organisms filled with holes. On the other hand, comb jellies, also known as ctenophores, are soft blobs covered in feathery cilia. The question regarding which came first has been debated for the past decade in scientific journals. The answer to this question will tell the world which organism is the closest living analogue of the first-ever animal. So, the stakes are pretty high. All animals share characteristics such as being multicellular, being eukaryotes, and being consumers. We all have a common ancestor which lived at least 550 million years ago, inhabiting the ancient oceans. However, the appearance of this animal is unknown. This is why scientists are now turning to modern species to find out more about the first animal. Evolutionary biologist Antonis Rokas claims that scientists are wondering about the ancestor’s complexity, genes, and traits. At first, researchers came to the conclusion that sponges were the sister group of the first animals. However, new evidence came to light that pointed to the comb jellies. Morphologist Claus Nielson was able to use this information to find relevant details about the anatomical and molecular characteristics of the ctenophores. This allowed him to create two possible scenarios: one as sponges coming first and one as comb jellies coming first. In doing this, he was able to see which traits the groups would have lost and gained in each scenario. Both scenarios are arguable. Sponges themselves are not that complex. They cannot move quickly, and can only consume minuscule particles. The sponge coming first scenario involves a gain in complexity, since groups of this organism would gain body systems such as the digestive and nervous systems. On the other hand, the comb jelly coming first involves a loss in complexity for the sponges since comb jellies already have these body systems. This article allowed me to gain insight on an arguable issue, still consuming the minds of the brightest scientists of today. This text allowed me to think about what I had never thought of before, so many organisms fill the wonderful home that we call Earth, but which came first? Which was the trailblazer that following animals branched off from? This article left me wondering about the future of science and hopeful of new, relevant evidence leading to the answers of many earth shattering questions, including those regarding our animal ancestors.
This week I read “A New Clue to How Life Originated”. Caitlin Cornell showed large bright spots she saw in her microscope to her supervisor, Sarah Keller. This was an exciting event, as it associates with questions scientists have asked about the origin of life. All cells have DNA and its counterpart RNA, proteins, and a membrane made from fatty acids. The earliest forms of life also had RNA, proteins, encompassed in a membrane. Something interesting the article pointed out is that life first arose in salty oceans. Salt and certain ions destroy the fatty-acid membranes of the cells, which places the cells in a problematic state. As the article asked, I wondered how then could life form in salty environments. However, Caitlin Cornell and Sarah Keller supported that the membranes withstood salt and magnesium ions, as long as they’re in the presence of amino acids. This fascinating information that they learned helps us understand why fatty acids and aminos support each other’s stability in cells even 3.5 billion years after the first cells formed. The article opened my eyes to how important research is, and how we will always have questions to answer in relation to biology.
This week I watched “ Four parasites Too creepy to exist.” I was intrigued to earn about the different types of parasites, especially since these were claimed as “ creepy” Prior to watching the video, I had already known that they find a host cells and take in their nutrients, so i was curious to find out how these “ creepy” parasites would complete that task. The parasites were the parasitic barnacle, tongue-eating isopods, frog mutating worms, and the giant corpse flower. The frog mutating worms affect frog growth and development, causing them to either have extra legs, or be short of them. The parasitic barnacles find their hosts in crabs. These barnacles grow inside the crabs, and get nutrients from it, similar to a regular parasite. The tongue biting isopods target the mouths of fish. They use its mouth as hosts and live in its gills. The giant corpse flower is one of the larger set parasites and flowers in the world. They take nutrients s from vines. What is interesting is that even though these are plants, they cannot photosynthesize. The parasite i found to be most interesting is the parasitic barnacle because it can completely change the way a crab functions , and even transform the femininity of a crab.
I read the article, "A Battle Is Raging in the Tree of Life." I found looking at the two possibilities from which today's animals have stemmed as some sort of competitive pedestal that these species were combating for, and I loved it. Scientifically speaking, most people have believed that the sponge came first and everything stemmed from that. But later in 2006, a genetics study changed that, pointing to the comb jellies instead. Repeatedly, several scientists have found research that proves both came first, so what actually came first? Dr. Nielsen, an 81-year-old zoologist, looked into this. He believed that sponges came first but there are obviously many people who combat that. In turn, there's still no concrete answer. And the same is said for things like how many times has the brain evolved? The author goes on to mention that at times, these discussions can become more than just biology.
The article that I chose to comment on this week was about the discovery of the vast amount of new tiny proteins that were discovered. They are fewer than 50 amino acids in length, so it is very likely that they were never known by their unique folding shape. The understanding of these proteins could lead to a better understanding of human health, and maybe even a new drug discovery. Scientists Ami Bhatt says the functions of proteins are more likely to be found by studying smaller protein, rather than larger proteins. However, they were not able to easily study these proteins because of their tiny size. They decided to compare the small-protein-coding genes to many samples, but however, she was able to figure out later that tens of thousands genes were part of the tiny proteins, which showed over 4000 related family groups. Lastly, they anticipate that these small proteins will be easier to study and understand, so this could be a very important area for biology in the future.
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I read the article " A battle is raging in the Tree of Life" because it intrigued me as I have a little background knowledge on sponges. I know that they were called the simplest animals as they only have 2 germ layers. This article dow in evolutionary origin, there is some debate between whether sponges or comb jellies are the closest living analog of the first-ever animal. The article depicts on how although simple sponges are, as they don't have any organ systems and onply two germ layers they may not be the closest thing to the first evelutionary animal. The first creature was a single-celled prokaryote living in the ocean and like many organisms today share similar features, scientists are looking at existing species to shed more light on the single celled prokaryote. In the article, Dr.Nielson said “I’m 81 years old, and I’ve been a zoologist since my 20s,” he said. “My whole concept of the animal kingdom would crash with this ctenophores-first idea.”. His idea is revelutionary as if comb jellies were the first organism, many of the existing animal kingdoms would have tro be re-orginized as some of the orginization was based on the idea that the sponge was first.
This week I read the article, "Human microbiome churns out thousands of tiny novel proteins." Ami Bhatt, a scientist, had discovered that that microbes both within and outside humans are creating proteins. Before, I only thought of bacteria as some sort of disease or virus. After reading this article, I now understand that bacteria is so much more complex and diverse. Researchers found extremely tiny proteins which were previously unknown. It is extremely important to fully understand these proteins because they could uncover numerous mysteries about the human body which are still unknown to this day. Since these proteins are very small, it is very easy for researchers to study them and identify their functions and significance. Discovering the secrets behind these proteins could further many other areas of study such as medicine and other functions of the human body. I am curious to know the purpose behind these miniature proteins because these proteins are definitely serving a purpose, we are just not sure which purpose it fills.
Evolution is a major topic in biology and it explains many things, like animals special to their habitat and also where humans came from and is why i read the article, "A Battle Is Raging in the Tree of Life." All animals have one particular characteristic in common, we are multicellular. We also have the same common ancestor which inhibited the oceans millions of years ago but no one knows what it really was. the purpose of this study is to find that common ancestor by comparing common animals. For years, sponges have been though of as the first animals but in 2008, a genetic analyzes pointed to comb jellies. Personally, i believe that the sponge is the common ancestors of animals based on many evidences said in the passage, the main being that comb jellies have a nervous system and the ability to eat. Meaning that if they were the first animals, they would have to give up their digestive systems since sponges dont have them. This concept seems very absurd so i believe that sponges were in-fact the first animals millions of years ago.
Mahdhav Rawal
I found the article about “A Battle Is Raging in the Tree of Life” interesting because it explored an topic that i never had interest or understood. Dr.Rokas mentioned that major changes to the phenotype are simple changes in the molecular level. This makes it all together abstract to formulate a perfect “common ancestor”. If we believe that the nervous system is the key system for our consciousness then Dr.Nielson’s approach would be deemed insignificant and overlooking the major details. The article mentions that the squeezed out information about the common anatomical and molecular characteristics, this could also mean his theory is right because of molecular similarities being more reliable than physical characteristics.
I decided to watch the video about parasites by Scishow. Parasites are organisms that make their living by taking resources from the host, another organism. Usually, parasites end up harming the host. One type of parasite mentioned in the video is called the Tongue-Biting Isopod, which belongs to a group of crustaceans called cymothoids. This group is well known to attack fish. They have a pattern of going for the mouth through the gills, and eventually, the males grow into females as they suck on the nutrients from the bloodstream of the fish. Sometimes female isopods can grow up to 3 centimeters, which can block the fish’s waterways and therefore make infected fish smaller and less healthy. Another parasite mentioned in the video is the Parasitic Barnacles. These parasites take control of a crab’s body and force it to serve them. They belong to a group called the rhizocephalan. According to the video, “While the female larvae infect a host, the male larvae seek to attach to those receptacles on an implanted female. When a male has successfully attached itself, it shrivels into a very tiny, very simply adult form.” I found this video interesting to learn about because parasites make up about ⅓ to ½ of life on Earth, which is a large amount.
I watched the video "4 Parasites Too Creepy to Exist." The video describes four parasites and what they do to survive and reproduce. A parasite is an organism that survives by taking resources from another living being, usually harming the host. Scientists estimated that anywhere between one third and one half of all life on earth is made up of parasites. The first parasite is often called Tongue-Biting Isopods which being to a group of crustaceans called cymothoids. The parasite often stars out as a free swimming male larvae. They wander around the ocean until they spot a fish. They they go into the fish's gills and check is any other parasite is occupying the fish's mouth. If not then it will move into the mouth and bite down, holding it in place. Once the parasite has fixed itself, it transforms into an adult female. Other male parasites will Steele down in the gills and make occasional trips to the female to mate. A fish that is infected ends up with one female in its mouth and up to five males in its gills. As a result the fish that are infected become weaker and smaller. That is because the fish can't breath as well. Female parasites can grow up to 3 cm which can greatly negatively affect the mouth of water that goes into the fish's mouth. The next paste was called Ribeiroia, these at flatworms that affect frogs. Usually affecting the growth of legs. Some frogs we're seen with extra legs, which other frogs were seen to be missing a leg. In an extreme case two frogs were seen with four extra legs. The parasites life cycle begins in the faces of birds or mammals. Once the mammals excrete into water the eggs of the parasite hatch and then the swimming larvae infect snails. Then the reproduce asexually seating hundreds more of themselves. Then the parasites find a tadpole and infect their skin near the developing limb buds. And as the tadpole grows up it grows up instead of normally going limbs, the parasite makes it grow more or less limbs. And the final part of its lifecycles ends with the frog being eaten by a mammal due to the altered limbs. The third type of parasite are parasitic barnacles. Female parasitic barnacles seek out crabs or crustaceans that are like crabs. Once they find a suitable host they borough inside and become adults inside. Soon a barnacle body comes out of the bottom of the crab. This is called the externa. Female larvae infect a host but male larvae attach to the externas. The interna infiltrates the body fo the host and then makes the crab actually protect the parasite instead of easily killing the parasite. Which the crab could do. This is because the parasite grows in the brood chamber where the crab usually holds its eggs. The parasite is mimicking a clutch pf eggs. And if the crab is male the parasite will slowly make the crab a female. When the new parasites are ready to be born the flaps its exoskeleton, something the carbs do for their own babies. Lastly the fourth parasite mentioned in the video is known as the giant corpse flower. Also known as the worlds largest flower. These flowers smell strongly of rotten flesh, which then attracts flies allowing them to pollinate. These flowers attach themselves to grapevines and take in the nutrients from that. Oddly these flowers don't have the ability to go through the process of photosynthesis. Making it a type of parasite that can't live on its own. Which is known as an obligate parasite. Another odd fact about this flower is that this parasite seals the hosts DNA, and scientists are still unsure why. But the presume its because it alters the DNA in a way where its easier to infiltrate the host.
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