In Wrangham’s view, fire did much more than put a nice brown crust on a haunch of antelope. Fire detoxifies some foods that are poisonous when eaten raw, and it kills parasites and bacteria. Again, this comes down to the energy budget. Animals eat raw food without getting sick because their digestive and immune systems have evolved the appropriate defenses. Presumably the ancestors of Homo erectus—say, Australopithecus—did as well. But anything the body does, even on a molecular level, takes energy; by getting the same results from burning wood, human beings can put those calories to better use in their brains. Fire, by keeping people warm at night, made fur unnecessary, and without fur hominids could run farther and faster after prey without overheating. Fire brought hominids out of the trees; by frightening away nocturnal predators, it enabled Homo erectus to sleep safely on the ground, which was part of the process by which bipedalism (and perhaps mind-expanding dreaming) evolved. By bringing people together at one place and time to eat, fire laid the groundwork for pair bonding and, indeed, for human society.
We will now, in the spirit of impartiality, acknowledge all the ways in which cooking is a terrible idea. The demand for firewood has denuded forests. As Bee Wilson notes in her new book, Consider the Fork, the average open cooking fire generates as much carbon dioxide as a car. Indoor smoke from cooking causes breathing problems, and heterocyclic amines from grilling or roasting meat are carcinogenic. Who knows how many people are burned or scalded, or cut by cooking utensils, or die in cooking-related house fires? How many valuable nutrients are washed down the sink along with the water in which vegetables were boiled? Cooking has given the world junk food, 17-course tasting menus at restaurants where you have to be a movie star to get a reservation, and obnoxious, overbearing chefs berating their sous-chefs on reality TV shows. Wouldn’t the world be a better place without all that?
Raw-food advocates are perfectly justified in eating what makes them feel healthy or morally superior, but they make a category error when they presume that what nourished Australopithecus should be good enough for Homo sapiens. We are, of course, animals, but that doesn’t mean we have to eat like one. In taming fire, we set off on our own evolutionary path, and there is no turning back. We are the cooking animal.