““Everyone knew that at some point in history, early humans got access to a big supply of protein, which allowed their brains to expand like a thirsty sponge in a bucket of water. Our brains kept growing until they were seven times larger than the brains of any comparable mammal. They also sucked up an ungodly number of calories; even though our brains account for only 2 percent of our body weight, they demand 20 percent of our energy, compared with just 9 percent for chimps.””
