Documentary Redraws Humans' Family Tree Hillary Mayell for National Geographic News January 21, 2003 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. Modern humans, he contends, didn't start their spread across the globe until after that time. Most archaeologists would say the exodus began 100,000 years ago—a 40,000-year discrepancy. Wells's take on the origins of modern humans and how they came to populate the rest of the planet is bound to be...