Sunday, April 5, 2009

Do You Believe in Metamorphosis?

The next time someone asks you whether you believe in evolution, you might ask them that question in reply. I know now that the phrase “ontogeny recapitulates phylogeny,” which I learned in college biology, has been largely discredited. Still, what is metamorphosis if not evolution accelerated?

What alchemy is this that wrought frog from fish, and butterfly from worm? What kind of miracle results in such a drastic transformation over an easily observable span of time? Even the most basic understanding of metamorphosis does not lessen its magic. I am regretting that I did not take an insect physiology course while I was in college, but we no doubt know collectively more now than we did in the early 1980s.

At an informal gathering of local entomologists a few years ago, a graduate student made a presentation on metamorphosis that revealed to me some startling facts. Chief among them was the (obvious, in retrospect) idea that a butterfly starts to take shape well before the pupal stage. Inside the caterpillar, adult body parts begin their genesis as nodes called “imaginal discs.” How enchanting and appropriate is that term? Imaginal discs. The caterpillar cannot possibly imagine itself as a butterfly in the cognitive sense, but the idea that at a cellular level it most certainly does is truly fascinating. That the timing of each stage of development is regulated by “juvenile hormones” and other biochemicals is no less astonishing. The power of molecular-level chemistry is mind-boggling.

Given the complex, yet rapid process of metamorphosis, is it really a stretch to think that speciation through evolution cannot take place over an even longer span of time? It certainly seems plausible to me. The bottom line, however, is that we can no longer afford to waste time debating the merits of evolution versus creation theory. Extinction is most definitely not a theory, and unless we direct our collective scientific and theological efforts toward species salvation, it won’t matter how they came to be in the first place.

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