Bipedalism has very ancient roots in the human family tree.  Some traits of bipedalism show up in hominid ancestors from as much as 7 million years ago. But, how and why did walking upright on two legs become such a human trait? This article from Erin Wayman for the Smithsonian.com does a great job of breaking down the most recent hypotheses and the history of the study of human bipedalism.

Smithsonian has a new online article series called “Becoming Human.”  It’s a great overview of how the traits we consider “human” came to be.

Click Here for Story on Smithsonianmag.com.