Dr. Spencer Wells on the Genographic Project's First Results | Big Think

Dr. Spencer Wells on the Genographic Project's First Results

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Back from the verge of extinction.

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Spencer Wells:

Spencer Wells is a leading population geneticist and director of the Genographic Project from National Geographic and IBM. His fascination with the past has led the scientist, author, and documentary filmmaker to the farthest reaches of the globe in search of human populations who hold the history of humankind in their DNA. By studying humankind's family tree he hopes to close the gaps in our knowledge of human migration.

Wells's own journey of discovery began as a child whose zeal for history and biology led him to the University of Texas, where he enrolled at age 16, majored in biology, and graduated Phi Beta Kappa three years later. He then pursued his Ph.D. at Harvard University under the tutelage of distinguished evolutionary geneticist Richard Lewontin.

His landmark research findings led to advances in the understanding of the male Y chromosome and its ability to trace ancestral human migration. Wells then returned to academia where, at Oxford University, he served as director of the Population Genetics Research Group of the Wellcome Trust Centre for Human Genetics at Oxford.

Following a stint as head of research for a Massachusetts-based biotechnology company, Wells made the decision in 2001 to focus on communicating scientific discovery through books and documentary films. From that was born The Journey of Man: A Genetic Odyssey, an award-winning book and documentary that aired on PBS in the U.S. and National Geographic Channel internationally. Written and presented by Wells, the film chronicled his globe-circling, DNA-gathering expeditions in 2001-02 and laid the groundwork for the Genographic Project.

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TRANSCRIPT:

Topic: Dr. Spencer Wells on the Genographic Project's First Results

Spencer Wells: Probably the coolest thing to come out of the genetic results is how small the human population probably was. If you go back to around 70 to 80,000 years ago, we were very nearly extinct, probably the total number of people living in the world at that time and again we were still all living in Africa could have fit into a small symphony hall, around 2000 people, maybe even less and so we nearly went extinct and this was probably due to climate shifts that were occurring around that time. We were in the midst of the last ice age, things really started to get bad between 70 and 80,000 years ago. There was a massive volcanic eruption in Sumatra that is Mt. Toba that erupted around 74,000 years ago. The combination of these factors probably drove the human population very close to extinction and we came back from that and we figured out a way to survive these horrible climatic conditions and that probably primed the pump if you will to allow us to go out and explore the rest of the world and actually make proper forays into the part of Asia, off into Europe, South East Asia, Australia and ultimately into the Americas between 15 and 20,000 years ago. So the evidence is that we started to leave between 50 and 60,000 years ago following a coastal route along the south coast of Asia, beach combing our way along, living on, you know, marine resources, shellfish, probably doing a little bit of fish trapping. We rapidly made it down to South East Asia to Australia by around 50,000 years ago when humans show up in the fossil record there. There was a later migration between 45 and 50,000 years ago according to our data that came via an inland route, cross the Sahara at a point when the Sahara was actually a very nice place to live. Every 20,000 years or so due to fluctuations, the way the earth precesses in its orbit, the way it rotates and this causes shifts in the way the monsoon rains fall in Africa. Every 20,000 years or so the Sahara’s actually a pretty nice place and it was an extension of the grasslands of East Africa around 50,000 years ago and this allowed people to slowly move up into northern Africa, out into the middle east and that led them on their way to the rest of the world.

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