something only the wildest speculator would want in her portfolio. But I want to go back to Dobzhansky’s claim about how to make sense in biology. I teach evolutionary theory, how that theory came to be, and about the products of evolution (animals and the inanimate or quasianimate majority of the living world). In each course, I am struck—and students are annoyed—by how often something can sound logical, but fail to be “biological.”
When What’s Biological Isn’t Logical, That’s Evolution By Sta n P. R ac h o ot i n , p ro fesso r of b i o l o gi c a l sc i en c es
Note: This is the second in a continuing series of “What everyone should know about …” essays by MHC professors. The great evolutionary biologist Theodosius Dobzhansky said that “Nothing in biology makes sense except in the light of evolution.”
It is true that any topic in biology, and many scientific questions that impinge on our lives, can be illuminated in revealing and useful ways by considering evolution. How and why does HIV change? Why did domesticated plants and animals happen? What new human diseases are
cooking themselves up, and how are they “stirred” by our domesticated animals and “seasoned” with our antibiotics? Can genes from one organism prosper in another? What happens during a mass extinction? What were consciousness, language, and prayer cobbled together from, before there was consciousness or language or religion? These are reasonable questions, some of which have pretty good (though alarming) answers. We can say with a high level of confidence that life will prosper and advance for billions of years to come. However, the one life form with consciousness, language, and religion— were it looking for a mortgage—would definitely be “subprime,”
When we visit Stony Brook below Upper Lake, for example, we find freshwater sponges and freshwater bryozoans. They are all female, and while there are many “coed” streams elsewhere, here, the creatures dispensed with sex. And they persist quite nicely, in spite of all we think we know about the point of sex. It’s evolution. On the other hand, an aphid that clones daughters will, with her brood, overwhelm your potted plant. As the plant succumbs, aphids appear with wings; some are males for the first time in generations. These aphids mate and fly off to cause mischief elsewhere. Evolution explains that, too. I use specific scientific disciplines to explain some of the stories I teach: why a sea anemone has a pharynx; why our genes work in a cascade; why our bodies and those of flies wear out while the
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