It was these changes that distinguish our species from fellow primates. Most scientists agree that the first change occurred because of a meat diet but the second change from Homo habilus to Homo erectus has never been adequately explained. Wrangham believes the explanation lies in “catching fire” and cooking food.
Drawing extensively from the fossil record for changing anatomy, observations of modern-day primates and the behavior of hunter-gatherers, as well as the science of cooking, digestion and nutrition, he argues that our evolution from ape to human, physiologically to big brains and culturally to pair bonding could only have begun when our ancestors began to cook their food.
We have interviewed a number of people on these pages in the past few years who are advocates of the raw food movement — promoting it as the most natural and healthful way to eat.
Scientific evidence, however, has shown that cooked food, whether vegetables or meat, provides significantly more energy than food in its raw state. Cooked food is easier and quicker to digest and can also be digested with a smaller gut, releasing metabolic energy for the development of a larger brain.
Because cooked food is easier to eat, it requires less time and strength to chew, which allows the size of the jaw and teeth to be reduced, freeing the mouth for a greater range of vocalizations.
You must burn calories to release the calories from the food but because raw food is harder to digest, it requires more calories to get calories out of it and you get fewer of them anyway. So, cooked food produced a hominid that chewed less and had more time to think.