Summer Assignment: 8.24.10

Malaria, Sea Grapes and Kidney Stones: A Tale of Parasites Lost

Ninja Bat Whispers to Sneak up on Moths

Two interesting posts about evolution this week, highlighting two interactions which drive much of evolution: parasitism and predator-prey. The first article is about a member of the Apicomplexan group. This group contains the human parasite Plasmodium which causes malaria. The particular research highlighted in the post details one particular Apicomplexan named Nephromyces which infects a tiny marine animal called the sea grape. Turns out, the Nephromyces my be protective for the sea grape against kidney stones. So it seems that this parasite and host have formed a mutualistic relationship - this means that they both derive benefits from the interaction. But the story doesn't stop there, as the researchers found a bacteria species living inside the protozoan which may help break down the kidney stones. So there may be two mutalistic relationships here, like some kind of biological Russian doll set.

The second article discusses the biological arms race that often occurs between predator and prey. Predator evolves some technique to hunt its prey...predator evolves a way to evade this hunting technique...predator evolves refined hunting technique...prey evolves refined escape technique...etc,etc. This is evident in many forms, such as camouflage or mimicry, and even seemingly simple adaptations such as fast running speed. In this particular case, moths which are hunted by bats using echolocation have evolved very sensitive ears to pick up the signals and avoid the bats. There is one species of bat, the barbastelle bat, which has evolved a countermeasure to the moth hearing (so a counter-countermeasure, I guess). The barbastelle bat is quiet. Very quiet. Turns out, if we could hear them, bats would be as loud as jackhammers. Little, furry, flying jackhammers that will bite you and give you rabies. I actually really like bats and am looking into enticing some to move into my backyard to help with a mosquito problem. Of course, if they were as loud as jackhammers, i would just keep covering myself in Off whenever I am out there for more than five minutes.

Whenever I hear people talk about how boring biology is, I always think about evolution research, which is constantly showing us that we really have no idea exactly how complex the world around us is.

Summer Assignment: 8.17.10

Bacteria Can Have a "Sense of Smell"

Not really all that surprising that bacteria can "smell," or simply detect airborne chemicals. Smell is directly related to taste, as anyone who has tried to eat their favorite meal with a cold can attest to. The only difference in smell and taste is how the chemicals are delivered to the receptors: direct contact for taste and airborne for smell.

The interesting part of the research, to me at least, was the fact that the bacteria respond to different "smells." Ammonia, for example, triggers the formation of a biofilm.

Biofilm is a major cause of infection on medical implants such as heart valves, artificial hips and even breast implants. Also known as 'biofouling' it costs the marine industry millions every year, slowing ships down and wasting precious fuel. But it also has its advantages. Certain biofilms thrive on petroleum oil and can be used to clean up an oil spill.

Algebra and Circuit Breakers
Lots of great points in this post about the current state of math and science education/knowledge. There is a general lack of understanding about math and science in the general public, and I do not just mean that people don't know what DNA stands for, of how to factor a polynomial. It is more important to understand math and science as processes, ways of thinking about and solving a problem, rather than a set of facts to be memorized. I think that this is very nicely illustrated in the linked post by the story of the circuit breakers.

How often do we hear people say "Oh, I'm not a math person, you figure out what the tip should be for lunch"...what if someone said "Oh, I'm not much of a reading person, you tell me what the menu says." Those two statements are really not that different, yet one is OK, and the other signifies a breakdown in the educational system. Why is that? Why is it socially acceptable (and in some cases preferable) to be "not a math/science person" while not being a language person is unheard of. Not knowing how to critically think, weigh evidence and draw a logical, evidence-based conclusion is as integral to math and science education as knowing the difference between verbs and nouns are to language education.

And don't tell me that basic reading is a fundamental life skill while finding percentages is not. The current economic situation has been partly blamed on people's misunderstanding of basic math. And anyway, my point is not about math and science factual knowledge, but using the skills gained in studying them to navigate life.

[The] skills you learn in math go well beyond learning to plug numbers into the quadratic formula. Math is about systematic thinking, and systematic thinking is what built human civilization. Without the ability to think systematically, we'd all be stuck huddling in caves, hoping the lions didn't eat too many of us tonight.

And yes, I am treating math and science as one here, as the author of the post does. One of the other major problems with education is the compartmentalization of learning. This isn't math class, why are we talking about numbers? This is [class x] not [class y], why are we talking about [topic from class x]??? Because everything is connected, and seeing those connections is the hallmark of an educated mind.

Hopefully, if I have done my job as an educator, after taking AP Biology, you will begin to see and appreciate those connections.

Summer Assignment: 8.10.10

Pees and Carrots

Sustainable fertilizer may be easier than we think. This is actually a much bigger issue than it seems, since the current practice of using fossil fuels to create fertilizers for industrial farming means that we use 10 Calories of energy for every 1 Calorie of food produced. This is obviously not a sustainable practice for very long. The question is though, will people be willing to pee on their salads before eating them?

Using Blue Whales' Perfect Pitch to Drive People Insane

FINALLY!! Biology has a mad scientist. Too long only chemists and physicists were allowed to hatch mad schemes to take over the world.

I have only to gather a pod of blue whales in the harbor of some Pacific coastal town and make them direct their song landward. The synchronized infrasonic hum, deafening yet inaudible, has the potential to cause anything from high blood pressure to incipient madness in the townspeople. At the very least, it'll produce a hum that some people can hear and others can't, which would be unbearably annoying.

Summer Assignment: 8.3.10

More links than usual this week, each one to a slightly longer article...but they are all about sex!















[Image: mating sand wasps, Alex Wild]


Gonna Have a Fungal Good Time

When Love Shocks

Water Strider Blues

Darwin, Sex and Dada

I don't have much to say about these posts, just pick one or two to read over and let us all know what you found interesting.