Evolution and the female orgasm

I admit, I was sucked in by a link (via kausfiles) to the Huffington Post. How snarky of me. But I couldn't resist this one:

Wouldn't it be delicious if the female orgasm were the thing that tips the scales in favor of the Intelligent Design crowd? It would make for a great closing argument: "The female orgasm is so complex and strange, it could only have come from God. The reason there is no evolutionary purpose to it is because there is no evolution!

Turns out it's a post by Arianna herself reacting to a New York Times article about Elisabeth Lloyd's new book, The Case of the Female Orgasm: Bias in the Science of Evolution. Arianna's post makes little sense of the issue, which is yet another reflection of how evolutionists manage to speak past most of the public. I'm sure there's a special joy to be found in becoming a one-liner on Letterman, but it's not exactly the pinnacle of scientific communication.

This is actually a rather old scientific issue now, since Lloyd and her sometimes collaborator, the late Stephen Jay Gould, have presented their arguments for many years. The basic issue is whether female orgasm itself has an adaptive purpose or whether it is merely a side effect of developmental processes that affect fetuses before sex differentiation occurs. Many potential adaptive purposes have been suggested, from the idea that females have orgasms more often with certain kinds of desirable mates, and therefore seek them out, to the idea that the contractions accompanying orgasm may create a suction effect to draw sperm further into the reproductive tract. The problem with any hypothesis is accounting for the fact that a large proportion of human sexual intercourse occurs without any female orgasm, and many females never experience orgasms.

To me, the Times article is interesting, and I recommend it for an overview. It doesn't follow standard journalistic protocol, but instead goes through a laundry list of different theories of the putative adaptive value of orgasm and Lloyd's objections to them. This makes for dry reading, but it does give a fair presentation of some of the alternatives (albeit with little detail). However, it leaves certain parts of Lloyd's argument unclear. For example, Lloyd indicates that

there was no doubt in her mind that the clitoris was an evolutionary adaptation, selected to create excitement, leading to sexual intercourse and then reproduction.

But if this is true, then what is the big deal about explaining female orgasm? Sure, it is possible that sexual arousal and excitement are adaptive while orgasm per se is not, but this seems increasingly like a distinction without a difference. And if female sexual excitement is adaptive, and if the nerve pathways are developmentally homologous between males and females, then why would anyone imagine that selection would necessarily cause the sexes to diverge in this aspect of their sexuality? Clearly one needs to read the book to find out the real story here.

Anyway, Gretchen tells me I have no business blogging about this because of my Y chromosomal status. And come to think of it, it is pretty twisted for Arianna Huffington to be touching all our lives this way....