Sex, Politics, and Evolution

Evolution is such a hot topic that it was the subject not only of yesterday's Doonesbury, but of this week's Savage Love column. For those who aren't familiar with it, Savage Love is an extremely well-informed sex column. So if you're offended by sex, please stop here.

In response to a query from a woman who couldn't experience orgasm, columnist Dan Savage turned to Salon.com writer Tracy Clark-Flory, who drew on evolutionary biology for insights. She pointed to the theory that female orgasms evolved because they were advantageous in males, just as nipples evolved in many male mammals because they were advantageous in females, and didn't do the males any harm. Such anatomical crossovers happen because the sexes share the same genes, with the exception of some on the Y chromosome. And developmental biologists say we start out in utero with proto-versions of both types of genitalia, so every part in one sex has an analogue in the other.

In a male, orgasm is clearly adaptive.  A male who didn't experience them might quit before he was finished, which would be detrimental to his reproductive success. Or in some cases, he might stay with the act too long at the expense of his own survival.

I learned a lot about this topic during the three years I wrote my previous column, Carnal Knowledge, which was always about sex and, usually, also about evolution.  There, I explained various theories purporting that female orgasm improves reproductive success, as well as the theory that it rode along with the male one as a byproduct.

The byproduct view was extolled by Stephen Jay Gould, who took some flak for it, but it served to make an important point about evolution: Everything isn't here for a reason. Our bodies are full of byproducts – things that were adaptive in the opposite sex, or in our ancestors, whether they were other apes or even, going further back, fish.

Clark-Flory wrote that she initially found the byproduct idea distasteful, but then realized it could be freeing, not just for the woman writing Dan Savage about her orgasm trouble, but for the anyone who ever wondered if a quirk of sexual anatomy or feelings or behavior was "normal". Those of us who read Savage Love know that's a pretty common concern among human beings. Sometimes it's good to remember that we weren't created or designed. We aren't degenerate versions of some ideal human. In evolution, there is no ideal.

And that will be the topic of an upcoming Planet of the Apes column.