Um the gay gene wouldnt preclude its not related to overpopulation (pssst they already found the reason animals become "gay" last time I checked story telling apes were still animals "thats homo sapiens ie: humans",unless your of the camp of course that humans are somehow superior to all life on earth because we use tools and write things down?,if so check out Dolphins and Whales brain to body mass ratio (how we measure intellectual capacity overall ).

Last time I studied evolution Genetic traits become predominant when their found advantageous.....Not randomly(thats how they start in the first place ), Of course there is those who think its always been part of the human condition and that we all are "a little gay" some more than others (look at ancient greece...large numbers of homosexual's and completely acceptable in society). Once again doesnt preclude Homosexuality being a biological response to over population. Sorry studies have been done on thousands of species they all come out the same, to think humans are somehow special would be illogical. (thats why in EVERY zoo over 40% of the animals in the zoo engage in homosexual behaviour...they're crowded...In a world where we can move freely from place to place(being the dominant species) these genetic characteristics(or behaviours) would not neccessarily be limited to crowded areas, as the precursor's of such gene's (produced by overpopulation) would pass it on when they moved, a genetic trait wouldnt simply dissappear it'll spread. (contrary to popular belief many gay couples reproduce....unfortunately for the "gay gene" camp less than 20% of those studied produce "gay offspring" thus throwing the "gay gene" argument for a loop. It would also mean its not a "normal behaviour" but a mutation that cropped up and survived for a reason (how evolution works). I'm inclined to believe from available evidence that its completely natural and is a reaction (brain based) to over population (or else bi sexuality and being "straight" would also be genetic...Studies however do not support this). Look at the greater body of evidence . But I would love to see the study to look at it, I'll use an open mind too. I'd be very interested in seeing it personally (and any other studies on any other subject you wish to post, I'm always up for reading a scientific journal ).