I’m finding it difficult to connect these two statements.

If this new gene is in a chromosome that is shared between the sexes (which is the most probable option) and it does not decrease the probability of reproduction of the other sex as much as it improves the other, then it will be chosen by evolution.

Therefore, homosexuality and bisexuality are inevitabilities of evolution. Any thoughts? — Qmeri

Sounds plausible to me and is a thought I’ve had before too. But then I’m pansexual so only being attracted to one sex has always seemed a little “unnatural” / culturally conditioned to me.

There are no inevitabilities in evolution, sans death.

Is it suggesting there could be a homosexual gene?

I just added to the text:

even if it increases the sexual interest of a man to men. — Qmeri

So, sorry for that. But evolution in the long term takes pretty much all "easy" mutations into account. What we know of evolution seems to imply that psychological mutations that do not need a major increase of things like processing power or something else seemingly large physical change in the brains, seem to be relatively easy mutations. So, things like mental interests most likely happen very quickly. With evolution nothing is certain, but many things are almost inevitable.

There are no inevitabilities in evolution, sans death. — StreetlightX

With evolution nothing is certain, but many things are almost inevitable. — Qmeri

So, it's besides the point. Hard to say these things efficiently without compromises, but technically you are right. Sans death ;)

Okay, I think I get it. But if a man had a sexual interest in other men and only other men how would that gene be passed on?

Okay, I think I get it. But if a man had a sexual interest in other men and only other men how would that gene be passed on? — Brett

If this was genetic and not learned, then according to this theory, the genes that made him be like that would increase the changes of the other sex to reproduce even more than it decreased his.

Ironically forcing that man to act heterosexual would increase the amount of those genes in the gene pool.

But I'm not saying that this is the only reason for homosexuality - I'm just saying that this makes it practically a necessity of evolution.

Just realized: forcing homosexual people to act heterosexual increases the amount of "homosexual genes" in the gene pool. Maybe the widespreadness of homosexuality is not because of this small inevitability of evolution, but because of our historical cultures that have forced homosexuals to act heterosexual.

But the start of homosexuality is probably because of this quirk of evolution.

But I'm not saying that this is the only reason for homosexuality - I'm just saying that this makes it practically a necessity of evolution. — Qmeri

Sure, I understand that. I think where I might be tripping up is that you mean ‘an interest in other men’, that the gene creates. But doesn’t that mean he would not be homosexual, but only have an interest in men?

Sure, I understand that. I think where I might be tripping up is that you mean ‘an interest in other men’, that the gene creates. But doesn’t that mean he would not be homosexual, but only have an interest in men? — Brett

Well, all I can answer for that is that nothing seems black and white in psychology. Is any homosexual purely homosexual? We know that many men have true disgust for sexual relations with women. And the same but opposite for women. Can we pinpoint the exact genes or learned reasons for those? probably not. But we can say that a sexual interest for the same sex is inevitably increased by this quirk of evolution.

Though, if I understand correctly, that “homosexual” gene can always be passed on by a heterosexual couple, correct?

Though, if I understand correctly, that “homosexual” gene can always be passed on by a heterosexual couple, correct? — Brett

At least, by heterosexual action as I understand sexuality, yes. Male sperm needs to impregnate a female. Not taking into account some weird developments of modern technology.

Also a thought I have had before. :up:

The problem here is that the role of evolution and genes in determining complex behaviors is by no means clearly or well understood. My view is that homosexuality is genetically determined, but perhaps indirectly. Rather than genes acting directly on males, it may involve genes acting in the female to produce a sequence and timing of hormones during early pregnancy that results in males being homosexual. Your description sounds like another indirect mechanism, But again, we really don't know.

We have 46 chromosomes (23 pairs) but we have a huge number of genes, some of which operate indirectly. A given gene may have a significant effect on development by turning another gene off or on. A lot of genes have direct effects, and many genes have effects by turning others on and off.

our behaviors don't track back to many specific genes, so far anyway. I'm gay. There are most likely a whole set of genes that operate directly and indirectly that result in my finding a particular guy irresistible, and making the necessary moves to have sex with him, and perhaps live him for decades - just like there would be for heterosexual attraction.

Women who emphasize sports often get very "manly" attributes like stronger jaws and smaller breasts. That seems to imply that many "sexual attributes" are not strictly genetically forced.

And most of our genome is shared between men and women. Only 2 of our 46 chromosomes are distinctive between the sexes. So, most of our mutations and new genes happen in chromosomes that are shared between the sexes. Therefore a mutation can happen, which improves the ability of one sex to reproduce more than it decreases the ability of the other sex to reproduce.

For example: a new gene can make a woman more sexually interested in men in a way that improves her chance to reproduce. If this new gene is in a chromosome that is shared between the sexes (which is the most probable option) and it does not decrease the probability of reproduction of the other sex as much as it improves the other, then it will be chosen by evolution even if it increases the sexual interest of a man to men.

Therefore, homosexuality and bisexuality are inevitabilities of evolution. Any thoughts? — Qmeri

Imagine if everyone was homosexual. Birthrate = 0. End of humanity or whatever species became completely homosexual. In other words, selection pressure would work against the homosexual gene.

However, if, as you suggest, there's a reproductive benefit to homosexuality, then sure, a species will maintain a certain population of man-man or woman-woman action.

Homosexuality is hard to explain physiologically, because we don't have an explanation yet. It might be forthcoming, but as of yet, no yeti.

Evolutionarily it happens, if it is mutation-driven. There are lots of mutations occurring every day, and actually in every birth, but some mutations are more common than others, and most are dead-end evolutionarily.

But what I said here everyone knows on these forums.

Imagine if everyone was homosexual. Birthrate = 0. End of humanity or whatever species became completely homosexual. In other words, selection pressure would work against the homosexual gene. — TheMadFool

Even if you make the assumption that individuals which are homosexual are exclusively homosexual in sexual interest, that doesn't mean they don't reproduce. Moreover, even if they do not reproduce, it doesn't follow that any particular genotype that may result in homosexuality is not adaptive (or deleterious). It could be that a tendency towards exclusive sexual interest in individuals of one's own natal sex comes along with other traits that are adaptive (or just non-deleterious); it could be that the development of homosexuality is down to gene expression (perhaps due to natal hormonal environment).

Moreover, twin studies reveal that the development of sexuality in humans can't be reduced solely to genetic causes; like often hypothesised site mutations (as in ) or "the gay allele"; rather it seems that one's genotype plays only a facilitatory role - providing a genetic predisposition or consistency - with developing exclusive homosexuality.

Not in my opinion.

In my opinion it's a product of our uncivilized man made playground, and how it distracts us from what's important.

Here are two facts:

People can want to sex change because of the condition of their genitalia.

People will be gay when they experience imaginary disruption.

Walled-in, winding-road and small-boxed environments, disrupt imagination.

Not having access to clear sky and horizon, has a huge effect on your thought process. It's disadvantageous to a whole genetic type, it's a whole different train of thought.

Even if you make the assumption that individuals which are homosexual are exclusively homosexual in sexual interest, that doesn't mean they don't reproduce — fdrake

homosexuals reproducing... :chin:

Moreover, even if they do not reproduce, it doesn't follow that any particular genotype that may result in homosexuality is not adaptive (or deleterious) — fdrake

Agreed but all that I wanted to say was that if survival is the goal as evolution claims it is, a 100% homosexual species would die off in a flash: which means even if gayness is in some way adaptive it will never cross a certain threshold determined by requirements of minimum birth rates. It also seems plausible that if the gay gene is to maintain itself in a species it better not do anything that could upset the reproducing heterosexual population and thus homosexuals will, on the whole, remain a minority in any given species.

homosexuals reproducing...:chin: — TheMadFool

Sexual preference, no matter strength, no make babby, no exclude babby. Sometimes babby come from gay man or woman and partner because like partner and want child. Sometimes drama. Sometimes artificial insemination. Sometimes woman have child for close gay friend. Sometimes person gay for loooong time and fuck other sex for loooong time until reaches personal epiphany, or until moves away from restrictive social context.

This has been your yearly dose of sex ed.

Sexual preference, no matter strength, no make babby, no exclude babby. Sometimes babby come from gay man or woman and partner because like partner and want child. Sometimes drama. Sometimes artificial insemination. Sometimes woman have child for close gay friend. Sometimes person gay for loooong time and fuck other sex for loooong time until reaches personal epiphany, or until moves away from restrictive social context.

This has been your yearly dose of sex ed. — fdrake

:rofl: :up:

The benevolant uncle

This sounds plausible if we don't get into details, but that doesn't amount to inevitability. Staying at the same level, unencumbered with expertise, here is an alternative scenario that may sound just as plausible: All genes that can affect sexual attraction are specific to the sex chromosomes. This, if true, would neutralize your argument.

's is the most plausible hypothesis that I have heard. It's quite possible that there is more than one pathway, including perhaps the classic site mutation, aka the "gay gene." But that couldn't be the dominant mechanism, for a number of reasons. Yes, it is not wholly impossible for gay people to reproduce, and yes, gay people may have benefited their community, and thus indirectly their gene pool. But the negative selection on the specific gene would be too strong to overcome those mitigating factors. The rest of the genome may benefit, but not the "benevolent uncle" gene, which will be selected against. However, if part of the gene pool conspires to sabotage another part, as in the scenario described by @Bitter Crank, that could be a viable strategy for evolution to pursue.