[News] Do Gay Animals Change Evolution?

[Moontanman]

Do Gay Animals Change Evolution?

 

Homosexual behavior seems pointedly un-Darwinian. An animal that doesn't pass along genes by mating with the opposite sex at every, well, conceivable opportunity, seems to be at an evolutionary disadvantage. So what’s in it for the 450-plus species that go for same-sex sex?

 

Do Gay Animals Change Evolution?: Scientific American

[Boerseun]

Seen in the light of individual selection, homosexuality does seem to be a bit of a dead-end street. But I suppose homosexuality operates more in the sphere of group selection.

 

Amongst primates, homosexuality is rife. It serves not so much as a purely sexual act, but more a social tool, where conflicting parties make up by "presenting" themselves to their opponents (of the same sex) when conceding a fight. The one winning the "fight" will then mount the loser, and the dominance hierarchy is strengthened.

 

This goes for both sexes: Amongst chimpanzees (pan troglydites), sexual couplings are almost 50% homosexual. Amongst bonobos (pan paniscus), sexual couplings are less than 30% heterosexual, for both sexes. I've read about this study in the last two or three days, I'll go and look for a link for you.

 

So it might be that it's to the group's benefit to have homosexuality as a calming tool, where groups with a homosexual bent will be less inclined to seriously hurting each other where there's no tool for lessening rampant testosterone levels.

 

Very much the same process might be involved in rising homosexuality where humans are confined to unnatural environments of high population pressure, like jails or big cities. But this is mere speculation. Being primates, after all, the mechanism might very well be present in humans.

 

But apart from that, it should also be said although homosexuality is common amongst various primate species, no case is known of primates being exclusively homosexual.

 

If your inclination towards homosexuality might save you from being mauled to death (by presenting to the alpha), you might live to fight another day. And, who knows - one day the alpha might turn his back and you can have a quickie with one of his prime females. That should give you a better chance of survival than the exclusively heterosexual males who will fight to the death.

 

It does not really explain exclusivity amongst human homosexuals - unless it's merely a magnified mechanism that's part-and-parcel of our genome.

[InfiniteNow]

In addition to the well articulated points above by Boerseun, it also confers benefit in the rearing of their kins children, parallel in many ways to the grandmother hypothesis.

 

Also... a quick correction to the OP... You mentioned "450-plus" species which go for same-sex sex." It's actually above 1500 species.

 

http://hypography.com/forums/biology/17804-is-homosexuality-unnatural-2.html#post254621

 

 

Finally, I haven't put forth this idea anywhere yet, since I don't think it has much merit... but it's certainly possible...

 

It could be related to hyperactive sex drives. The idea is that selection has favored hypersexuality itself, such that those animals more inclined to "sex in general" out competed and out reproduced those animals which were not inclined to "sex in general."

 

Following from this, it's possible that we've evolved to have more of a "sex is good" than "reproduction is good" mentality as pertains to evolution, and this leads to the emergent property of differing sexual tastes... whereby some like opposite-sex sex and others like same-sex sex... and still others like various other combinations.

 

So, my point... it's quite possible that evolution itself is what changed straightness and gayness, not the other way around.