Shows the path taken by human migrations out of Africa, by locating and following markers in the DNA. The narrator is an American scientist, Spencer Wells, and a very adept commentator and explainer. His film crew travels to many world sites, starting with a group of "bushmen" in Africa, which are the oldest bloodlines yet found - the origins of all the rest of us.
He shows how the several migrations led to colonization of Australia, eastern Asia, and how those Asians led to the crossing of the Bering Straits and the eventual splitting into all the "native American" tribes. Other Asians (the oldest is in Kazakhstan) led to the population of Europe. All this in 2000 generations - since 40,000 years ago.
Amazing stuff.