Gay Marriage and Evolutionary Theory

I’ve officially changed my position regarding gay marriage. I used to oppose gay marriage because it seemed to confer no reproductive advantage to the organisms, and believed that this sort of behavior ought to be discouraged. However, thinking about it last night, I’ve realized two things.

First, although homosexuality is maladaptive for the organism in a pure Darwinian sense (you don’t get your genes in the next generation by mating with another dude), gay marriage will not erode the basic biological underpinnings of regular marriage.

The institution of marriage has evolved because it generally serves our species reproductive interests. For the male, it normally guarantees exclusive mating rights with a particular female (or females in polygynous societies). This substantially raises the likelihood that he is the father of the female’s offspring. The male therefore can safely invest energy in the offspring, raising the likelihood that it will survive and successfully reproduce.

This arrangement benefits the female because it tends to guarantee a healthy supply of male parental investment in her offspring. Even in polygynous societies, a male will only be able to acquire as many wives as he is able to support.

Gay marriage will neither interfere with exclusive mating rights or guarantees of male parental investment – the real “family values.”

Second, not only will banning gay marriage will not discourage maladaptive behavior, I don’t want it to.

Let’s assume for a second that if gay marriage was banned, then gay men would go and marry women. This means I would have to compete with an influx of better-dressed men as I search for a mate. Girls already seem to have a strange infatuation with gay guys – why would I encourage them to compete against me in a zero-sum Darwinian game?

So by supporting gay marriage, I keep potential competitors out of the gene pool. The species as a whole may not benefit, but I will.