Man smart, woman smarter, crooned the late Robert Palmer. Well it appears our vegetarian ancestors were smart enough to discover protein rich meat, which, as it turns out, made them smarter -- and slimmer.
From National Public Radio:
"Our earliest ancestors ate their food raw — fruit, leaves, maybe some nuts. When they ventured down onto land, they added things like underground tubers, roots and berries. It wasn't a very high-calorie diet, so to get the energy you needed, you had to eat a lot and have a big gut to digest it all. ... 'What we think is that this dietary change [to meat] around 2.3 million years ago was one of the major significant factors in the evolution of our own species,' Aiello says." Read the story here.