Cooking up intelligence.

Scientific American interviews a primatologist – well, a biological anthropologist named Richard Wrangham – who believes humans evolved big brains because of cooking:

Your theory that cooking spurred the evolution of modern humans occurred to you while you were sitting in front of your own fireplace?

Yes, about 10 years ago, right after the start of the academic term, I was thinking about what stimulated human evolution. The fire just started drawing me in to the comparison with chimps, because I tend to think about human evolution through the lens of chimps: What would it take to convert a chimpanzeelike ancestor into a human? And as I thought about how long we have had fire, I realized what a ridiculously large difference cooking would make. It’s a very simple thought; anyone who had ever taken an anthropology course should have had it long before this.

Just how would cooking make a difference? What’s wrong with raw food that chimps eat?

I know chimpanzee foods fairly intimately, I’ve tasted the great majority of the things I’ve seen them eat, and I know what a huge difference there is between a chimpanzee diet and the human diet, because we cook. And that set me off thinking about whether or not humans really could ever survive on a raw diet. And my instant assumption was no, because of my experience with chimpanzee diets, which said to me we couldn’t possibly do this—so that raises all these fascinating evolutionary questions. I’d had the experience of seeing a close relative eating all those foods and seeing how unpleasant they are and how difficult it would be for humans to survive on a diet like that. Maybe people assume that the kinds of places in which humans live would have apples and bananas dripping off the trees, but it’s not like that.

What are the foods like, then?

The typical fruit is very unpleasant, very fibrous, quite bitter; the net effect is that you would not want to eat more than two or three of them before running for a big glass of water and saying, “That was not a pleasant experiment, I hope I don’t get sick.” They’re not nice to eat. Not a tremendous amount of sugar in them. So there were very few fruits that I’ve tasted that I can actually imagine getting a stomach for because most of them are unpleasant to eat. Some make your stomach heave.