Homosexuality is very simple to explain. One variant nucleotide of the DNA chain during conception and poof. A male body has a female desire or visa/versa. You can't force it and you can't take it away. The cause? Who knows? Anxiety, depression and anger comes with it but that is man made. Homosexuality isn't about sex, its about love that happens to require sex as a coping mechanism of desire and normality. If you removed the genitalia from 2 male homosexuals and took away their sexual desire, they would still love each other and carry on as a heterosexual man and woman do but without the sexual behavior.

Not every human's destiny is procreation (a good thing) and I don't believe homosexuality is a "mistake" of evolution. Hasn't homosexual behavior been a part of human culture for thousands of years? I believe it involves some minimal biological influence, but that environment, early childhood experiences (including early exposure to same-sex stimulation or images, or even trauma/abuse), play a much bigger role than biology.
Regardless, American culture, ESPECIALLY RELIGION, has instilled so many hangups and issues with regard to sexuality. If any of us can find a mate that makes us happy, we should consider ourselves lucky and go with it. Just don't hurt anyone (even if they beg you to) ....

The pragmatic debate (I don't care what you do in your bedroom as long as you don't hurt people):
Nope. Not a mistake but a natural needed inclusion.
In times that population is over booming without high mortality it is beneficial to have participants who will opt out of procreation. In times of high parental death it is important to have members who might be willing to help with child rearing but isn't already burdened. As a result you find an open acceptance of homosexuality in populations that growth us no longer needed and it is usually highly rejected in places where the mortality rate and or birth rate are not favorable.

It's gawd will, let it be!
????????

Everything in nature is natural. There are reasons why things are as they are, but we might not know or understand those reasons. In that sense, both homosexuality and homophobia are completely natural and must be accepted and respected.

I personally don't care what another person's sexual orientation is. I also believe that people have sex for more than just procreation.

Why even bother with the question? Does it hurt you what people do in the privacy of their bedrooms, unless of course it is not consensual? You seem to have forgotten that we don't only have sex for the purpose of procreation, oh hell that would be horrible.

I like a definition of natural that saiys that if our body can do it without a tool or modifications. Then it is natural.
Unnatural is to filter water, use clothes, cook food etc.
But answering your question. Yes there are some hypothesis that says that homosexuality has a role on evolution and is present in many species.

There is a TON of homosexual activity in the animal world; humans are no exception. As long as you have enough heterosexuals to keep the species going, or enough people who are not exclusively homosexual, things are fine.

Variation in genes, it just is what it is. Personally I don't care about the reason.

The study of twins shows that it is not likely genetic in that if one male twin (you did not indicate lesbian), is homosexual, only 20% of the his twin identifies as such which is the estimated rate for the general population. It it were genetic, one would expect that all twins would be of the same sexual orientation. Nevertheless, psychologists agree (or so I have read), that once the sexual orientation is established in early childhood, it cannot be changed. Therefore, it serves no purpose to discriminate, maltreat, etc. on the basis of sexual orientation...just from a pragmatic point of view and to do so would be bulling for bulling's sake. But, it will be interesting to hear from gays and lesbians on the subject.

I suffer from low T and have actually had a "lesser" libido dating all the way back to my teens. I am hetero but I just don't have the raging hormones others seem to feel. never have. neither did my father or my grandfather. my biological children also had low hormonal levels and one, born my daughter, now identifies as a male. I can't help but think that has some role in gender self-ID. I think it starts somehow biologically and is reinforced with social influence. maybe the biology spurs it. or vice versa. I hope some day they figure it out so people aren't traumatized as they are now.

How do any of the answers to what you are asking impact your life?

If it's an inherent desire and attraction, it is NATURAL.
That is all you need to know.

Now go forth and troll no more.

If there is a gay or lesbian gene, the reason why that gene could be propagated through the generations would be because the families somehow benefited from having a gay man around or a lesbian woman around who would help raise their nieces and nephews.

You think we need more overpopulation?!? Oh, wait, youthink orphans should only be placed in "traditional" homes, if none of those available, too bad so sad.
WTH are you saying, exactly?