Where did the human species originate? Why are tropical peoples much more diverse than those at polar latitudes? Why can only Japanese peoples digest seaweed? How are darker skin, sunlight, and fertility related? Did Neanderthals and Homo Sapiens ever interbreed? In Humankind, U. C. Davis professor Alexander Harcourt answers these questions and more, as he explains how the expansion of the human species around the globe and our interaction...