>>11500085>its a mistake of natureIf it was a "mistake", it would have been selected out a long, long time ago. Instead, something like 10% of the population is gay/bi. This means that at the very least it's not an active detriment, and may actually be desirable.
One of the more popular ideas is the "gay uncle" hypothesis. The more older brothers a male has, the higher the chance is that he will be gay. It is possible that this evolved to give support to his other siblings and their children. The gay brother historically wouldn't have had children of his own, so he would essentially be a "free" adult to help out where needed, and improve his siblings + their children's reproductive success.
