Arthur_Tuxedo wrote:
1. No other animal has members that are exclusively homosexual. Other animals may engage in homosexual behavior, but it is not exclusive and is much less common than in humans.
This is false, there are examples of homosexual animals that
always show a preference towards the same sex when that option is open to them, to the exclusion of any number of opposite sex. There's a rather famous example in
sheep in that they definitively show preferences.
Darth Wong wrote:I'm sure he did. So what? Does he provide any evidence whatsoever that in a species that generates near 50/50 male/female birth ratios, we evolved to be anything other than optimally heterosexual? Or just a half-baked explanation based on the assumption that there must be some good reason for every trait and variation?
I can give a few examples of the potential benefits for a biological homosexuality trait:
1) Though it wouldn't work for the majority in our society, due to attachment to abrahamic religious culture, in most human societies, guy on guy sex reinforced social bonds, hierarchy and morale. Having a few social "facilitators" that would actually choose this over breeding would help an overall population, it would reflect well genetically on his family if it got the society to look favourably on the family, and would be more likely to get his brothers mates (
having more older brothers makes you more likely to be homosexual), if the family was in good stead.
2) The biology that contributes to homosexuality in men might have a beneficial outcome in women, and might be an evolutionary trade-off, like sickle cell anemia.
3) Most human societies wouldn't have had access to enough resources to provide for all their adults either breeding or looking after growing children, therefore, if you keep having male children, having all of them breeders could endanger their success, having a gay brother would have another hunter/gatherer/warrior/nurturer in the society, with a genetic attachment to his brothers and the rest of his family without resources being sapped by new offspring.