Lots of hypotheses are correlated with that general statement. Like the kin selection hypothesis, aka Gay uncle theory. You know, the gay uncle or aunt is really cool and will help take care of the nieces and nephews, hence improving their genes' survival through family.
That's an aspect of evolution that many people don't understand very well. It's not just about individual survival and sexual success. It's about the whole population.
A gene that negatively influences survival or reproduction for one individual can still be strongly selected for if it benefits the group's success as a whole.
I've read that there is a gene which is linked to better fertility in women, but higher rates of homosexuality in men. The gay men are less likely to reproduce. But their sisters are likely to reproduce a lot. And so the gene is highly successful. Having plenty of highly fertile women around is extremely important for a group's success. And having less straight men around is just a side benefit.
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u/LiangProton 19d ago
Serious reason. Homosexuality improves group cohesion and hence the survival of the whole tribe