Interesting, sweeping account of the history of human population movements based on where genetics was in 2002. Some fascinating info about the Jews, Bushmen, Mitochondrial Eve, the Neandertals, and the Native Americans. After each chapter, however, I was left wanting more. Too much commentary and speculation mixed in with hard genetic evidence. While I appreciated Olson's insight that race is a biologically indefensible construct, he seemed, by the end of the book, to be gathering as many quotes by researchers as he possibly could to make the same affirmation. Yes, we get it. Race doesn't exist in our species. I also thought his foray into historical linguistics was a bit unnecessary. He tried somehow to claim that our linguistic history can tell us something about our genetic history. While this may be helpful to the past 5000 years, comparative linguistics tells us nothing about any proto-language, and to speculate about this is beyond his purview. Overall, OK book, but I'd be interested to see something more up-to-date by an actual geneticist, like Spencer Wells.