Fifty thousand years ago-merely a blip in evolutionary time-our Homo sapiens ancestors were competing for existence with other individual species, just like their precursors had done for millions of years. However something about our varieties distinguished it through the pack, and ultimately resulted in its survival while the rest became extinct. Precisely what was it that allowed Homo sapiens to be masters of the earth? Ian Tattersall, curator emeritus in the American Museum of Natural History, will take us deep in to the fossil record to uncover what made human beings so unique. Surveying a vast field from preliminary bipedality to language and cleverness, Tattersall argues that Homo sapiens acquired a winning mix of qualities that had not been the result of long-term evolutionary refinement. Rather, the final result surfaced quickly, shocking the world and changing it forever.