Well, I am very curious about what are the opinions on the subject.
If gay genes are naturally selected and homosexuality has been present in ancient times; how could homosexuality survived throughout this much time.
I think the whole homosexual movement is about equality and not really about what we can conclude as logically valid.
Epigenetics is when the genetic code is altered or affected by the environment- in this case the environment of the uterus during pregnancy. There is some decent evidence that homosexuality is caused by in utero changes, making it inborn but not genetically heritable.
Of course, recessive genes knock out this argument in the first place even if there was a "gay gene". There are many genetic syndromes that cause infertility that are passed on by recessive genes and only are expressed when both parents have a copy. Thus, the person with the syndrome can't have offspring themselves, but their siblings may carry a single copy of that gene forward in the population creating further members with the syndrome down the road.
There is also the fact that research has shown that in many animal societies, the female siblings of homosexual males have greater than average fertility rates. Since siblings share DNA, this perpetuates the genes forward in the population even if the homosexual member himself does not breed.
Not to mention that oppression of homosexuals throughout the years and the desire to "blend in" means many homosexuals DO breed.
Homosexuality is a lot more complex than an male-female genetic switch that causes you to be attracted to one gender as opposed to another. It's a complex thing caused by a large combination of cultural, social, psychological and personal factors. This argument also assumes that homosexuals in the past have always been able to be openly homosexual and not have to have put up a front of heterosexuality, up to and including reproduction, and that they would not have reproduced at all. Also, even if it were reducible to simple genetics, recessive genes would also nullify the argument.
Your tastes and tendencies are not scientifically defined by your genes. Thus, this whole debate is fundamentally flawed. Homosexuality has been around for as long as mankind, and it has never vanished, why would you want it to vanish? Just let them live and focus on your mortgage payments, redneck.
There is a theory regarding the rise and propagation of the gay gene. It might not have anything to do with the gene as such, but a different gene: hyperattraction to men.
Such a gene a woman would also be able to possess, making her hyperattracted to men, and therefore would have sex and (presumably) reproduce more, passing that gene on to her offspring. Any male children she would have would be hyperattracted to men, or, gay.
Otherwise, yes, obviously, seeing as gays can't reproduce naturally, the so-called gay gene should have vanished eons ago. But it hasn't, so there must be an alternate theory, the above example could possibly be one.