An evolutionary theory that I am quite fond of is the “gay uncle theory”. Basically it argues that because human babies require so much care compared to other animals, this certainly wouldn’t have been plausible for a monogamous couple to manage alone. Indeed, the nuclear family is a pretty new construct, and childrearing appears to have been a task shared across a community. The gay uncle theory suggests that if someone is gay and thus does not reproduce, this increases the caregiver to child ratio in that community/family. This may mean that homosexuality could confer a selective advantage at a community level, even if it makes an individual less likely to reproduce.
I find it an interesting theory because whilst it’s super speculative, there are plenty of examples where there are benefits to certain genes existing within a population, even if it reduces the relative fitness of some individuals in that community. In sub-Saharan Africa, for example, where malaria is prevalent, the gene responsible for sickle cell anemia exists at a higher frequency than in areas at less risk of malaria. This is because the sickle shaped blood cells confer some protection against malaria. Whilst having two copies of the sickle cell gene causes you to have sickle cell anemia, which can have pretty severe health effects, if you only have one copy of the gene (which we call having sickle cell trait) you’re much less affected (I know someone who only learned they had the sickle cell trait when they got into pretty high level athletics in college). For people in certain parts of the year world who have only one copy of the sickle cell gene, the increased resistance to malaria is enough of a boon to more than make up for the harm of having the sickle cell trait. If you have full blown sickle cell anemia, then that’s definitely a net negative for the individual, but at the population level, this is worth it because the population benefits from a certain level of the sickle cell gene being in circulation.
TL;DR: Population genetics can get pretty complex, and there’s a theory that gay people are actually evolutionary selected for within a community, at least to some degree.
An evolutionary theory that I am quite fond of is the “gay uncle theory”. Basically it argues that because human babies require so much care compared to other animals, this certainly wouldn’t have been plausible for a monogamous couple to manage alone. Indeed, the nuclear family is a pretty new construct, and childrearing appears to have been a task shared across a community. The gay uncle theory suggests that if someone is gay and thus does not reproduce, this increases the caregiver to child ratio in that community/family. This may mean that homosexuality could confer a selective advantage at a community level, even if it makes an individual less likely to reproduce.
I find it an interesting theory because whilst it’s super speculative, there are plenty of examples where there are benefits to certain genes existing within a population, even if it reduces the relative fitness of some individuals in that community. In sub-Saharan Africa, for example, where malaria is prevalent, the gene responsible for sickle cell anemia exists at a higher frequency than in areas at less risk of malaria. This is because the sickle shaped blood cells confer some protection against malaria. Whilst having two copies of the sickle cell gene causes you to have sickle cell anemia, which can have pretty severe health effects, if you only have one copy of the gene (which we call having sickle cell trait) you’re much less affected (I know someone who only learned they had the sickle cell trait when they got into pretty high level athletics in college). For people in certain parts of the year world who have only one copy of the sickle cell gene, the increased resistance to malaria is enough of a boon to more than make up for the harm of having the sickle cell trait. If you have full blown sickle cell anemia, then that’s definitely a net negative for the individual, but at the population level, this is worth it because the population benefits from a certain level of the sickle cell gene being in circulation.
TL;DR: Population genetics can get pretty complex, and there’s a theory that gay people are actually evolutionary selected for within a community, at least to some degree.