Humans are the only animal whose survival depends on controlling fire. A critical adaptive benefit is that cooking leads to large increases in net energy gain compared to eating our food raw. While cooking originated sometime between two million and four hundred thousand years ago, we still do not know exactly when our ancestors first tamed fire. Regardless of when it began, the control of fire had major consequences for human evolutionary biology by enabling a massive increase in free time, a wider, safer and richer diet, and bigger brains. The fact that humans are the only animals that are adapted to using fire and cooking means that other animals are not necessarily good models for understanding human diet, physiology and disease. Awareness of our unique human adaptation opens the door to improvements in calorie-counting, the prevention of obesity, and legal protection of vulnerable children. This talk is part of the Survival symposium, a series of talks focusing on evolution and the challenges of building a better, safer and more survivable future. Watch more of the Survival symposium: http://bit.ly/2iKfYRi Subscribe to The Leakey Foundation channel: http://bit.ly/2iDR5GO Survival was presented by The Leakey Foundation in partnership with Harvard University's Department of Human Evolutionary Biology, NOVA, NOVA Labs, SMASH, and WGBH. About the speaker: Richard Wrangham is Ruth B. Moore Professor of Biological Anthropology at Harvard University. He has conducted extensive research on primate ecology, nutrition, and social behavior. He founded the Kibale Chimpanzee Project in 1987. He is best known for his work on the evolution of human warfare, described in the book Demonic Males, and on the role of cooking in human evolution, described in the book Catching Fire: How Cooking Made Us Human. Together with Elizabeth Ross, he co-founded the Kasiisi Project in 1997 and serves as a patron of the Great Apes Survival Partnership (GRASP).