Finding Fault with Darwin

It has been pointed out that I read Seed magazine a lot. Here’s some more.

Homosexuality seems to be a bit of an evolutionary mystery. How could wanting to have sex with with your own sex possibly help to pass on genes?

Joan Roughgarden has some ideas. She notes that literally hundreds of animals exhibit homosexual acts, and she says that typical Darwinian sexual selection just doesn’t explain why. So she has her own explanation.

In short, she thinks that homosexuality is selected for in social creatures to help the communities bond. “It’s like grooming, except we have lots of pleasure neurons in our genitals. When animals exhibit homosexual behavior, they are just using their genitals for a socially significant purpose.”

My problems with this article and her theory:

The first thing is that she (or the journalist writing the story. Or both) is not up-to-date with evolutionary theory. For example, the article claims that sexual selection can’t explain masturbation, which is a “waste…of precious fluids” and doesn’t contribute to passing on the genes.

But no modern student of evolution thinks that every single action has to pass on the genes every single time. Evolution made sex enjoyable. The idea that we figured out how to have the enjoyment without the sex doesn’t change a thing. We don’t need a better explanation than that.

And the article, eventually, quotes a biologist who says just that:

I think much of what Roughgarden says is very interesting. But I think she discounts many of the modifications that have been made to sexual selection since Darwin originally proposed it. So in that sense, her Darwin is a straw man. You don’t have to dismiss the modern version of sexual selection in order to explain social bonding or homosexuality.

But for some reason, the writer didn’t read the quote, because he introduced it by saying that most biologists think that homosexual behavior among all these animals is “simply interesting sexual deviants, statistical outliers.”

Well, no. Saying that it’s explainable isn’t the same thing as saying that it’s an outlier. All this talk about killing the sacred cow is nonsense. There’s no sacred cow, and she hasn’t killed it.

My next problem with the theory may come from my ignorance of its details. Every example that the article mentioned was of a temporary kind of homosexuality. That is, she didn’t note an example of an animal that paired for life with its own sex. Each type of animal had sex with its own sex, but eventually mated with the opposite sex.

In humans, many homosexuals have no desire for the opposite sex. They’re literally uninterested, and remain uninterested their whole lives. This doesn’t blow her theory out of the water, but it does draw a distinct line between all other animals mentioned in the article, and humans.

[She does say that human attraction for one sex or the other is produced much more by social causes than we normally recognize. If we accept that idea, then I guess it could explain the difference.]

I’m glad that she’s out there making these claims and asking these questions, because I do think it’s obvious that homosexuality needs an evolutionary explanation. I mean, it’s here to stay, and it’s always been here, and it’s interesting to figure out why. But I don’t like presenting it as though there are only two ideas: hers, and old-fashioned stuff that doesn’t work.