A new study found that gay men may be predisposed to nurture their nieces and nephews as a way of helping to ensure their own genes get passed down to the next generation.

But scientists have been puzzled about how these genes are perpetuated, since gay males are less likely to reproduce than straight males. Basically, why haven’t gay people gone extinct?

One idea is called the “kin selection hypothesis.” Perhaps gay men are biologically predisposed to help raise the offspring of their siblings and other relatives.

“Maybe what’s happening is they’re helping their kin reproduce more by just being altruistic towards kin,” said evolutionary psychologist Paul Vasey of the University of Lethbridge in Canada. “Kin therefore pass on more of the genes which they would share with their homosexual relatives.” (Read More)