The last common ancestor of humans and chimps probably wasn’t much like either
By Erin Wayman
Picture it: an African forest 7 million years ago. An evolutionary split is under way. One species of ape is about to give rise to two distinct lineages; one leading to humans, the other to chimpanzees. What does this last common ancestor of humans and their closest living relatives look like?
For years, many researchers have just imagined a chimpanzee.
At first glance, that seems sensible. Even though chimpanzees are genetically closer to humans than they are to the other great apes, chimps appear to have much more in common with gorillas and orangutans than with humans. These apes all look so similar and primitive: shaggy beasts with long arms and handlike feet for climbing and swinging through trees. Humans are the oddballs in this group. With naked bodies, nimble hands, a two-legged stance and, of course, supreme intellect, it seems logical that hominids have changed much more over the last 7 million years than chimps and their ancestors. This kind of thinking has led some scientists to view chimpanzees as a kind of baseline from which hominid anatomy and behavior evolved.