Cooking, he says, has long been thought to be an optional cultural practice, like wearing jewelry. But really, he argues, cooking was the essential technological innovation that enabled us to produce the metabolic energy we needed to become human.
How? Cooked food is more digestible than raw food. And not just by a little, but by a lot. Learn how to control fire, use it to cook your food, and you free up extra energy — plus time that would otherwise be spent masticating. Spend that time hunting, and your metabolic equation gets even better.
via Kottke (again)