By the way, if you are an evolutionist, how do think homosexuality, if it is a normal condition, evolved as an adaptation that is beneficial to the propagation or survival of an individual's genetic traits?
Since any genes that might predispose toward homosexuality in humans haven't been identified yet, that's a little hard to answer. I have seen two ideas proposed, though:
* It might be that the genetic component of homosexuality is a "side-effect" of some entirely separate trait.
* Men with some "homosex gene" in early societies - those with functional extended families - perhaps were a significant help in raising their siblings, instead of heading off to form their own families. This, too, would perpetuate their genes, analogously to a worker bee raising its siblings even though it can't reproduce.
And then as Ned points out, there is quite a bit of research that points toward not genetic, but later-in-the-womb drivers, probably hormonal, that predispose some toward gayness.