Diet and Human Evolution
In this essay, I will argue that human evolution was primarily the evolution of a new diet. The key traits that set us apart from other great apes (bipedalism, tool use, social organization, and a larger brain) are all linked to diet. Our last common ancestor with chimpanzees lived sometime between 6 and 4 million years ago. It was probably similar to a chimp in appearance and behavior. Like a chimp, it ate mostly plant foods, with some animal foods. Although we are closely related to chimps, the human form has diverged from that ancestral form in many ways. The important differences are: Bipedalism. Hands shaped for tool use. Bigger brains. Language and more complex social organization. Smaller jaws and teeth. A smaller gut relative to body size. When we think of the differences between ourselves and the other apes, or other animals, a small gut is not what usually comes to mind. Neither is small teeth. We tend to focus on the dramatic differences in behavior and intelligenc...