In Catching Fire: How Cooking Made Us Human (Basic), Richard Wrangham dishes up an intriguing theory of human evolution.

On behalf of sushi haters like me, tell our readers how nature has fitted humans to eat cooked food.

Biologically, we are not well-adapted to raw foods. Our teeth and stomachs are small compared to those of chimpanzees or gorillas, because we don’t eat huge quantities of tough, high-fiber raw foods. Our large intestines are relatively small because we don’t have to retain and ferment raw food for hours. Humans don’t thrive on raw food—they lose weight, and women’s fertility is severely compromised.

How does cooking let us get more out of food?

Cooking increases the energy we get from starches because uncooked starch granules often pass through our bodies unused. Heat also denatures proteins, opening them up to digestive enzymes. Cooking softens foods and makes them easier to digest, so the energy costs of digestion fall. We use 10% of the calories we eat to digest our meals; some animals use much more, but we use little because we cook.

When did our ancestors start cooking, and how did it change them?

Small teeth and guts appeared around 1.8 million years ago, with Homo erectus, so cooking probably began then. Cooking enabled this species to evolve larger brains, which are energetically costly: if you have a small gut thanks to a cooked diet, the energy spared from maintaining the gut can fuel the brain instead. Cooking also changed the way we use our time. Apes eating raw food spend half their day just chewing. Humans spend under an hour a day chewing, freeing us for creative and social activities.

What inspired the first hominid chef?

Once our ancestors tamed fire, it probably wouldn’t have been long before a bit of food accidentally dropped into the fire; they would have plucked it out and immediately realized that it had been improved by cooking. We can say that because chimpanzees prefer cooked food; the tongue detects textures, like viscosity and grittiness, that enable an animal to discern the soft foods that are good for it.

How did cooking affect the relationship between the sexes?

In every society, the typical evening meal is cooked by a woman for a man. This is an ancient exchange: women give men food, men protect women’s food from being stolen. Women had to do the same thing every day: produce the evening meal. Men could hunt, go on war expeditions, lie under a tree and gamble—and still find dinner waiting. Because of cooking, women ended up chained to domestic responsibilities; men did not.