[kitawana]

> From a high level view, the idea that something that is so critical to species survival, like a sex drive, isn't largely genetic determined seems rather unlikely.

Actually I found that surprising to hear. We have so many social processes that in many cases discourage and reduce sexual behavior.

Marriage works against the survival of the fittest you might get from sowing wild oats, but it's almost universal.

Homosexuality, indeed, is a discouragement to species survival (if I understand your meaning correctly). Yet you're claiming it is unlikely that it doesn't originate in genetics?

I don't know, I mean, I basically agree with your final statement - that we don't actually have a discrete variable here even if we largely see discrete behavior (since we tend to prefer long lasting relationships, so if you're F45-55M then you'll probably focus disproportionately on finding an M partner).

And what it means to be a guy or a girl is definitely not genetic. Most of our interaction with sexual beings is "pants on". And those pants, and the nature of our interactions, is hugely cultural determined.

And I think most people have the experience of being attracted to a person without engaging in any sex-seeking behavior with them. And many people seem to have experience of the reverse.

Given the cultural and experiential components of sexual attraction, I really don't think genetics need to be worth that much. Maybe there's some contribution, but it doesn't seem to have much scope, nor does it need it.

[jayjader]

Marriage trades the advantage of sowing wild oats for the advantage of a pair of committed adults sticking around to raise the children to adulthood.

Survival of the fittest is useless if none make it to reproductive age (or the opportunity to reproduce), and humans are incapable of fending for themselves for at least the first couple of years of their lives. Simply reproducing with many is not a surefire way, and doesn't seem to be the optimal way, of guaranteeing that your genetic material endures.

Bret Weinstein has some interesting thoughts on the evolutionary merits of things like marriage and religion, I'd reccommend having a look at his work.

[DrScientist]

Another commenter has already dealt with marriage - it's much more complex that you think - just to add you appear to forget the womans point of view ( and genes ) entirely in you're assessment of the best strategy - where 'sow wild oats' obviously doesn't apply.

Also I'd have to say that one of the great successes of humans as a species is they are much more adaptable without genetic change than most - ie escaping our genetics is something to be acknowledged and celebrated not berated.

> Homosexuality, indeed, is a discouragement to species survival (if I understand your meaning correctly). Yet you're claiming it is unlikely that it doesn't originate in genetics?

I said the sex drive is likely largely genetic - note that there are two sexes! - women who are attracted generally to men and vice a versa - so both attractions would be encoded in the same genome - each by many factors. The question them becomes in any individual, which ones are switched on to what extent.

Genetic variation is a cornerstone of evolution, without it you can't genetically adapt or change.

Clearly sexual attraction involves the brain, which is one of the most adaptable organs in the body - so environment is very likely going to play a role - these things are not absolute.

Finally you seem to be under some illusion that the current state of humans is perfect adaption, rather than continuous work in progress against a constantly moving target.

[DrScientist]

Another point on attraction. Ideally you'd be attracted to a person that has the best 'genetic' fitness - ie ability to succeed. That's why things like symmetry are attractive ( a sign that development processes ran smoothly ).

However when it comes to things like predicting which body form will be most successful there isn't a single one as it depends on the environment. ie massive breasts and wide hips might be good for child rearing, but not very good for running. On the other hand in some situations a very large muscled man might be good - but not in a situation were food becomes scarce, or you need to be able to float.

ie there's isn't one form that fit's all niches - and so you'd expect there to be variation in body shape attraction as well.

So even putting aside the whole men/women different sexual attraction factors, even within one 'form' there will be significant variation.

[MaxBarraclough]

> Homosexuality, indeed, is a discouragement to species survival

Maybe not. Homosexuality has been very widely observed in nature. [0] My understanding is that modern biologists tend to take the view that evolution is, for whatever reason, not acting to eliminate it.

There exist genetic disorders like cystic fibrosis which, it seems quite clear, have no evolutionary 'upside', but which nonetheless haven't been eliminated by natural selection.

I believe most modern biologists tend not to put homosexuality in the same bucket, simply on account of how widespread it seems to be in nature.

I have to say I don't understand Dawkins' idea that homosexuality might be a 'misfiring' of genes, contingent on modern human life, given that homosexual behaviour has been observed in other apes. [1] [0]

Annoyingly Wikipedia has very little to say on this interesting question. [2]

> Given the cultural and experiential components of sexual attraction, I really don't think genetics need to be worth that much. Maybe there's some contribution, but it doesn't seem to have much scope, nor does it need it.

I don't see how that figures. One would surely expect evolution to 'care' a great deal about mate-selection. That's how we have Fisherian runaways, after all. [3]

[0] https://en.wikipedia.org/wiki/Homosexual_behavior_in_animals

[1] https://www.youtube.com/watch?v=IDmQns78FR8

[2] https://en.wikipedia.org/wiki/Homosexuality#Evolutionary_per...

[3] https://en.wikipedia.org/wiki/Fisherian_runaway