> but homosexuality does seem to be an important special case given that it typically means lack of descendants
For much of human history, that has been false. In many societies, there has been strong pressure to (heterosexually) marry, arranged marriages - with the result that most individuals with a homosexual orientation end up participating in heterosexual reproduction-so homosexuality is much less of an evolutionary disadvantage than you’d assume.
Modern Western society puts great emphasis on marrying for love, marrying on the basis of actual attraction rather than social pressure or political calculation, being “true to yourself” - and in such a society, a homosexual orientation does significantly reduce the odds of participation in classical heterosexual reproduction. But modern Western society isn’t normal in world-historical terms, what we consider “normal” is actually rather novel
For much of human history, that has been false. In many societies, there has been strong pressure to (heterosexually) marry, arranged marriages - with the result that most individuals with a homosexual orientation end up participating in heterosexual reproduction-so homosexuality is much less of an evolutionary disadvantage than you’d assume.
Modern Western society puts great emphasis on marrying for love, marrying on the basis of actual attraction rather than social pressure or political calculation, being “true to yourself” - and in such a society, a homosexual orientation does significantly reduce the odds of participation in classical heterosexual reproduction. But modern Western society isn’t normal in world-historical terms, what we consider “normal” is actually rather novel