What Trait Sets Humans Apart? Hint: It's Not Our Thumbs

Tracks from two humanlike species crossing paths in ancient Africa shed light on the tale of our specialized locomotion. 

Professor of Anthropology Jeremy DeSilva comments in an article in The Wall Street Journal about the fossilized footprints discovered in Kenya:  "The more territory you have, the more stuff you can munch on, and the more stuff you can munch on, the greater input of energy into the system, which can fuel a growing brain," says DeSilva. 

Read the article here.