I have a very vivid memory from my freshmen year of college of arguing with a friend of mine who had recently come out of the closet (to me, anyway) about whether or not it mattered if homosexuality was genetic. I thought it was crucial that we prove that there's a "gay gene"; after all, people can't begrudge someone for being born with a certain gene, now can they?

I thought then, somewhat naïvely, that proof of a gay gene would swing public opinion our way overnight.

She said it didn't matter. She said she was who she was, whether it was genetic or not.

Needless to say, she was right and I was wrong. And not just on the level of "Of course they're still going to begrudge people whether it's genetic or not; it's not about that" -- but also on the level of basic human rights. People don't need to prove that who they are wasn't voluntary before they get rights. They get rights by mere virtue of being a human being.

That's how it's supposed to work in this country. That's what we have to say to people.

Ever since that day, I've looked with a fair amount of disinterest upon the gay gene issue. It really doesn't matter. I don't care one way or the other whether homosexuality is genetic, learned, or a product of radical existential choice -- and neither should anybody else.

But some people do make a distinction between genetics and "choice," and for those people, I have an article from Britain's Independent, which purports to have found an answer to one potentially confusing aspect of the gay gene question, "If homosexuality is genetic, smart guy, and homosexuals can't have kids, why hasn't the homosexuality gene vanished from the gene pool?"

I've always assumed that this was because social pressures -- up to and including fear of violent death -- kept a majority of homosexuals in the closet until very recently, quite literally reproducing against their will.

But a new study suggests that the answer may be far simpler than that:

However, the problem is resolved if the genetic factors that lead to a predisposition to homosexuality and a corresponding lower fecundity in men cause a higher fecundity in the men's female relatives. Such a link means that genetic factors that predispose boys to becoming homosexual will never die out in a population because their sisters, mothers and maternal aunts will continue to spread the genes by having more than the average number of children...

One possible explanation for the finding that gay men have bigger extended families is that the bigger the family size, the more likely it is that some of the male offspring will be gay. However, this did not explain why the study found that the maternal aunts of gay men had significantly larger families than their paternal aunts, Dr Camperio-Ciani said.

Other research has indicated that at least some of the genetic predisposition to being gay was carried on the X chromosome, which men inherit through their mothers, but Dr Camperio-Ciani said that genes on other chromosomes were almost certainly involved in determining sexuality.

But it was this claim I found most noteworthy. I'd never heard this before:

Scientists have also demonstrated repeatedly that the chance of a man being a homosexual rises by about a third for each older brother he has. They found that a man with three older brothers was about twice as likely to be gay as a man with none. This suggests that there may be biological factors operating within the womb of a woman who has already given birth to a number of sons that increase the predisposition towards her next son being gay.

Really interesting stuff. Neither here nor there, as I above, but really interesting all the same.