- 1-the gene benefit non gay carrier
2-gay help raise sibling from the same gene pool, overall helping it.
3-gay can reproduce - 10% have biological children in the US-
4-gay come from "epigenetic": -hormone from mother before birth-
I wonder if @theAdvancedApe didnt already post something along the line.
I hate to throw cold water on anybodies thinking but a lot of gay men have children. Biological children they had because they had sex with a lady. Until recently gay men were usually married and giving it the old college try at their marital duties. (possibly while thinking of the men they would be with later)
Or: sexuality exists on a spectrum, and many people tend towards the poles because of cultural and social pressures. For instance, everyone thinks I'm straight because I'm married to a woman. Bisexual erasure is probably a big problem in sorting out how attraction to the same sex can be passed on genetically.
Bisexual Erasure is not only a band from the eighties but how the Straight and Gay communities pretend that some people are not Straight or Gay. I think most people have mixed and complex sexuality.
I'm almost 99.9% sure that this is the answer to the question posed. homosexual people are in heterosexual relationships and producing children. One could ask, well, does that mean every homosexual offspring has at least one (1) homosexual parent? Probably not, but I'm willing to bet the number is at least statistically significant and genetics makes up the other large portion.
what if gay marriage and adoption lead to reduced genetic fitness for Gay folks? No longer a need to be in the closet so no beards no kids from the beards -> reduced allele frequency -> no more gays. Gay liberation may lead to the extinction of Gay folks.
yeah, it's ironic. If anti-homosexual people want homosexuals to go away, wouldn't it be smart to stop forcing them into heterosexual relationships and reproducing?
I probably posted the recent answer to that evolutionary problem (but might as well tell it here) : There is a gene increasing sexual drive toward male. If you're a female, with that gene you'll get more offspring. If you're a male, you'll be gay. Overall the gene is good in an evolutionary standpoint, so the trait 'homosexuality' last. BUT... still no gene, or scientific explanation for female homosexuality.
I've hypothesized for a long time that it is a mechanism to stabilize population growth, as population becomes too high, the gene manifests itself more frequently. I don't have anything to back this up, but it's not mentioned in the article.
What you seem to be suggesting is that gay and straight are phenotypes that vary in a polymorphic way (in the simplest sense). I don't have any clue if that's possible and I really doubt that's what's going on but it's an interesting hypothesis.
I fail to see why evolution would at any point "do things" that would result in less propagation of the species. I think creepyinfant 's theory attributes a lot more intelligence to evolution than there actually is. Evolution is not smart. Evolution does not say "We need less people" and then make there be less people. Evolution is determined mainly by traits that encourage sexual success and propagation. Those traits can vary depending on circumstances. However, it seems very unlikely that we would evolve towards not propagating. I think b_b and theadvancedapes are better placed to speak on this than I am, however.
Well, we need to keep in perspective the timelines in which species evolve, and compare that to the timeline of human society. Homo sapiens has been a thing for roughly 500,000 years, civilization has been a thing for 10,000 years, and homosexuality as a conceptual construction has been a thing for maybe a century. Men have been banging men for a very long time, as we all know, but a Spartan who fucked a Spartan while marching toward some foreign war still eventually went home to his wife and made babies. Hence, even if there is a such thing as a gene "for" being gay, it wouldn't have started to work its way out of the genome until one could be gay, or you know, since the 70's. There are a lot of examples of homosexual sex in nature (elephants and bonobos, for example), but there doesn't (as far as I know) appear to be gay behavior (that is, exclusively favoring one's own sex, but I'm no behaviorist; I'd love to hear if anyone knows an example of this). I think homosexuality, as we currently know it, is a by product of society more so than a genetic aberration (although, as with most traits, I'm sure some are more genetically predisposed to such behavior when exposed to certain environments). So the short answer, is that if there is a gene for being gay, then it has only recently started to be whittled out of the genome, and for it to really be worked out it would require everyone who feels a little bit gay to stop breeding altogether. Not very likely.
You're right of course none of us know what we're talking about compared to the hubskiers who study this but I'd rather muddle about and form some intelligent questions to ask them once they come along instead of just learning the boring way.I fail to see why evolution would at any point "do things" that would result in less propagation of the species.
He posits overcrowding. That would have a selective effect automatically, right? But I don't think has anything to do with sexual preference.