Birds Do It, Bonobos Do It

What, then, does the homosexual behavior we see in other species, whether or not it involves lifetime pairing, tell us? For one, it suggests that among animals as among humans, sexual behavior is about more than reproduction. People unfamiliar with life in the wild often envision animals keeping their sexual contact to a bare procreative minimum, where male and female meet, mate and part as soon as the plumbing has everything lined up. Among some species that's true, but among many others sex plays a more complex social role in communication and in competition. Female vervet monkeys will mate outside the time they are fertile, for reasons that are still not understood.

At some level, everything living organisms do is about sex, because reproduction is how we pass on genes. From a biological standpoint, anything that does not further our own reproduction -- not the reproduction of others of our species, but our personal ability to perpetuate our genes -- is useless. Viewed in this manner, staying warm is about reproduction, evading predators is about reproduction and regulating our heart rate is about reproduction, because without all of these we cannot pass on our genes, and if we do them without passing on our genes they are evolutionarily meaningless. Still, even if being warm is about sex, no one expects to get pregnant by putting on a sweater. Even behavior that is related to sex doesn't have to lead immediately and inexorably to conception.

Going back to the bonobos, a student I once had in my animal behavior class was confused by the idea that sex was used to resolve social crises. Imagine, I said, that you and somebody else both wanted something, like a banana. If you were humans, maybe you'd fight over it, but if you were bonobos, you'd have sex. The student still looked puzzled. Yeah, he said, but then who would get the banana? By that time, I replied, you wouldn't care about the banana.