Note: I wrote this report in 2002, when Dr. Wrangham first published his thoughts on the connection between cooking and evolution. He has since written a fascinating book explaining and supporting his theories: Catching Fire: How Cooking Made Us Human . Highly recommended!
For years, anthropologists have told us that humans dominate the earth because they learned to make tools that could kill big animals that would give them more food so that they could survive. Dr Richard Wrangham of Harvard thinks they are all wrong. He thinks that man dominates earth because he learned how to cook.
Some anthropologists tell us that prehistoric humans were meat eaters, while others tell us that they were primarily gatherers of plants. If humans were meat eaters, why don’t you have large pointy teeth like other meat eaters such as a tiger? Or a lower jaw that juts out to catch prey like an alligator or dog? Humans have a flat lower jaw that couldn’t possibly grab prey for the first bite.
If prehistoric man ate primarily plants, then why don’t we have a multi-chambered stomach with stones so we can eat grass like a cow? Why don’t we have 40 feet of intestines like a rabbit does to have more space to break down the fiber in plants? And why do we have small teeth that aren’t able to grind grass like a horse’s teeth?
Dr. Wrangham, a Harvard professor of anthropology, attempts to explain why we are alive today and have not become extinct because we are so poorly designed. He thinks that humans survived because they learned to cook. Other anthropologists think that humans have been cooking for only 300,000 years, which is not long enough for major evolutionary changes to occur. Dr. Wrangham proposes that humans have survived because they were able to cook almost 2 million years ago, or 1.5 million years longer than previous evidence suggested. This could explain why we don’t have the teeth and digestive tracts like either plant-eating or meat-eating animals. Dr. Wrangham thinks it explains many other human features, too.
Many of the most abundant plants on earth cannot be digested by humans in their raw state. But cooking softens hard seeds, breaks down toxic and irritating substances in roots, seeds and leaves, and releases nutrients bound up in plant cells. Starchy foods such as potatoes, whole grains, beans and cassavas have 75-100 percent more digestible calories when they are cooked than when eaten raw.
Cooking also allows humans to eat meat. A dog can eat food right out of the garbage can because dogs and wolves have the most acidic stomachs of all mammals and their stomach acids kill most germs. If you ate spoiled meat, you would probably get an infection and die. Cooking kills most of the parasites and bacteria that flourish in meat and can be deadly to humans.
Since cooking allowed humans to eat both plants and meat and to get more calories from many plants than are available when they are eaten raw, humans had access to more food than all other animals and they survived when other species starved. Access to extra calories that are not available to animals who can’t cook may also explain why humans evolved with larger brains, which allowed them to dominate their environment wherever they went.
Several popular “paleo-diet” authors tell us that humans evolved without grains, beans or roots and so those foods should have no place in our diet today. Dr. Wrangham’s theory suggests just the opposite — that these are the very foods that allowed humans to develop into the small-jawed, small-gut, tall, large-brained, social animals we are today.
Originally reported in the New York Times, May 28, 2002