Humans are "strange" and smart animals, and according to a new study out in this month's issue of Genome Biology, it may be because we're such good cooks.
The authors compared apes and humans and found that the biggest, most important differences weren't in brain size, but in metabolism.
We had huge heads, but were still making "the same very boring stone tools for almost 2 million years." It wasn't until we started throwing mastodon onto the BBQ that things really got rolling:
In most animals, the gut needs a lot of energy to grind out nourishment from food sources. But cooking, by breaking down fibers and making nutrients more readily available, is a way of processing food outside the body. Eating (mostly) cooked meals would have lessened the energy needs of our digestion systems, Khaitovich explained, thereby freeing up calories for our brains….
The finding suggests that increased access to calories spurred our cognitive advances, said Khaitovich, carefully adding that definitive claims of causation are premature.
One interesting upshot: Raw food diets may not be a very good idea. The study's author blamed raw foodism for causing "very severe health problems."