Humans are hominoids. I know that sounds redundant. Blame anthropologists for a lack of taxonomic imagination. But the fact that I am a hominoid, I believe, is a significant fact. In everyday terms, it means that I am an ape.

Years ago, when my elementary school teachers delineated the tree of life in biology class, apes and humans were kept separate from each other. We belonged in our own group, the Hominidae, and the so-called great apes – orangutans, gorillas, and chimpanzees – formed another group, the Pongidae. The two groups were thought to have diverged from a common, primitive ape ancestor. But a combination of