Homosexuality serves no societal purpose. Good news is, with advances in genetics, we are coming closer and closer to discovering the potential "homosexual" gene or genes. If we can detect this genetic proclivity towards this anti-social behavior in the womb, we will be able to abort said fetus or use to gene therapy to address the issue. If this gene is discovered, and can be identified in the womb, I think many will go this route.
If homosexuality was genetic, natural selection would have weeded out homosexuality thousands of years ago. It should be an obvious fact that homosexuls would have had a lesser propensity to propagate, and therefore would have gradually disappeared over time.
Homosexuality is a phenomenon of over population, just like the other sexual deviations that raise their ugly heads in crowded populations.
You don't understand Natural Selection, and in this case homosexuals are "made" by heterosexuals, and always have been. Most homosexuals "make" heterosexuals BTW, which is the norm.
Natural Selection does not apply in this case. It would apply to people with two heads, if they had issue getting laid and were not a natural occurrence of one-headed people having sex. Homosexuality is a natural variation within human populations. It has always been there as far as we can tell and most of the time people didn't both to even name since men will **** anything, man, woman, child, livestock, anything they can catch with a hole in it.