Cooking food "tamed" our primate ancestors so humans could evolve?

That's Wrangham's theory, anyway. Cooking their food may have helped humans evolve, but the question remains open, in my opinion at least, whether or not humans are any improvement over chimps.

…The austrolopithicines, the predecessors of our prehuman ancestors, lived in savannahs with dry uplands. They would often have encountered natural fires and food improved by those fires. Moreover, we know from cut marks on old bones that our distant ancestor Homo habilis ate meat. They certainly made hammers from stones, which they may have used to tenderize it. We know that sparks fly when you hammer stone. It’s reasonable to imagine that our ancestors ate food warmed by the fires they ignited when they prepared their meat.

Now, once you had communal fires and cooking and a higher-calorie diet, the social world of our ancestors changed, too. Once individuals were drawn to a specific attractive location that had a fire, they spent a lot of time around it together. This was clearly a very different system from wandering around chimpanzee-style, sleeping wherever you wanted, always able to leave a group if there was any kind of social conflict.

We had to be able to look each other in the eye. We couldn’t react with impulsivity. Once you are sitting around the fire, you need to suppress reactive emotions that would otherwise lead to social chaos. Around that fire, we became tamer.…

A Conversation With Richard Wrangham
From Studying Chimps, a Theory on Cooking
By CLAUDIA DREIFUS

Published: April 20, 2009