It may throw a wrench in Noah's ark-stocking plans, but same-sex relationships appear in many animal species, reports LiveScience.com. The long list of animals that practice gay sex includes bears, penguins, gorillas, and dolphins, among others. But scientists question the act's evolutionary purpose, because it doesn't aid in reproduction. It may be an adaptation for nurturing offspring, or just a dry run.
"It could be a way that you strengthen bonds—that's one hypothesis," says one biologist. "Another is that it could be practice for heterosexual sex." (Read more gays stories.)