Tuesday, May 29, 2007

Becca's New and Hot #2 Week 9

I posted once this week, but when I read this article on moth evolution at breakfast this morning, I was prompted to write again. Says Nicolas Wade, the author of this article and also one of the books assigned for the Hum Bio core, "Every feature of a butterfly or moth, throughout its life from egg to adult, has been shaped over millions of years of evolution for specific purposes." Those specific purposes are basically escape from predators and parasites, for apparently monkeys and birds love to eat moths-- they taste "like raw shrimp." This made me think about fitness; are these ornate moths and butterflies more evolved than other species? Are they more fit for their environments? I also thought about the fallacy that some reading this article might commit: assuming that evolution had an end goal in "designing" the butterfly and moth patterns. Of course, evolution has shaped the moths and butterflies. But as we know, evolution did not shape the designs to promote survival; rather, the species with the most fit designs survived. Beyond helping me to synthesize some of the ideas to which we've repeatedly returned in this class, the article gives very interesting examples of butterfly patterns and their supposed purposes: those that look like dead leaves, those with patterns that accentuate movement to make them look like they're too fast to catch, those that camouflage well. Here are some pictures-- the first blends into tree bark, the second looks like sunlight streaming through a dead leaf, and the third looks like a dead leaf. I think it's a very cool application of what we know!

1 comment:

chickenpox said...

The pictures of the butterflies are a wonderful example of the beautiful results of evolution. There is so much focus on the imperfections and morphological uselessness that arises from evolution...(too counter the idea of creationism)...but this is a refreshing example!