Did Dining on Seafood Help Early Humans Grow These Big Brains?

Your brain is hungry. That big gray calculating machine in your head is an energy hog that needs lots of calories—more than the diet of fruits and plants that our distant hominin ancestors probably ate could provide. It's a mystery, then, just how human ancestors like Homo erectus—who were around when our craniums started to expand in a hurry—ate enough to start growing big brains. But buried in Kenya, a two-million-year-old hint has emerged: Those hominins started eating seafood way back then, archaeologists say. Near a place called Lake Turkana, archaeologists David Braun found two intriguing groups of items: The bones of fish, turtles, and even crocodiles with the scars of stone tools still showing, and stone fragments that Braun says come from the simple tools these hominins used to carve up the marine animals. He and his colleagues report the find of our ancestors' ancient feast in the Proceedings of the National Academy of Sciences.