I happened to catch this on PBS the other night. Has anyone else seen it or have any comments on it? It was interesting as all hell.
Program and article links at the bottom.
Here's a basic intro:
By analyzing DNA from people in all regions of the world, geneticist Spencer Wells has concluded that all humans alive today are descended from a single man who lived in Africa around 60,000 years ago.
Over the last decade, major debate on whether early humans evolved in Africa or elsewhere, when they began outward migration, where they went, and whether they interbred with or replaced archaic species has moved out of scientific journals and into the public consciousness.
Today, there is general agreement that Homo erectus, the precursor to modern humans, evolved in Africa and gradually expanded to Eurasia beginning about 1.7 million years ago.
By around 100,000 years ago, several species of hominids populated the Earth, including H. sapiens in Africa, H. erectus in Southeast Asia and China, and Neandertals in Europe.
By around 30,000 years ago, the only surviving hominid species was H. sapiens.
But when did we leave Africa and where did we go? Here's where opinions diverge widely.
Wells says his evidence based on DNA in the Y-chromosome indicates that the exodus began between 60,000 and 50,000 years ago.
In his view, the early travelers followed the southern coastline of Asia, crossed about 250 kilometers [155 miles] of sea, and colonized Australia by around 50,000 years ago. The Aborigines of Australia, Wells says, are the descendants of the first wave of migration out of Africa.
Many archaeologists disagree, saying the fossil record shows that a first wave of migration occurred around 100,000 years ago.
national geographic link
Journey of Man PBS Program link
Today, some six billion people are spread across the planet. But there was a time when the human species numbered only a few thousand and the world was a single continent: Africa. Then a small group left their African homeland on a journey into an unknown, hostile world. Against impossible odds, these extraordinary explorers survived and went on to conquer the earth. Their story can finally be told through the science of genetics. Dr. Spencer Wells, a 33-year-old geneticist, has been disentangling this epic story from evidence all people carry with them — in their DNA — inherited from those ancient travelers. Wells travels to every continent in search of the people whose DNA holds humanity's secret history, including Namibian Bushmen, Chukchi reindeer herders of the Russian Arctic, Native Americans and Australian aborigines.
The PBS station in my area shows that the program will be on this weekend again.