Yuval Noah Harari: What explains the rise of humans?

Seventy thousand years ago, our human ancestors were insignificant animals, just minding their own business in a corner of Africa with all the other animals. But now, few would disagree that humans dominate planet Earth; we've spread to every continent, and our actions determine the fate of other animals (and possibly Earth itself). How did we get from there to here? Historian Yuval Noah Harari suggests a surprising reason for the rise of humanity.