Spencer Wells (born April 6, 1969 in Georgia, United States) is a geneticist and anthropologist, an Explorer-in-Residence at the National Geographic Society, and Frank H.T. Rhodes Class of '56 Professor at Cornell University. He leads The Genographic Project.
Wells did his Ph.D. work under Richard Lewontin, and later did postdoctoral research with Luigi Luca Cavalli-Sforza and Sir Walter Bodmer. His work, which has helped to establish the critical role played by Central Asia in the peopling of the world, has been published in journals such as Science, American Journal of Human Genetics, and the Proceedings of the National Academy of Sciences.
He wrote the book A Genetic Odyssey (2002), which explains how genetic data has been used to trace human migrations over the past 50,000 years, when modern humans first migrated outside of Africa. According to Wells, one group took a southern route and populated southern India and southeast Asia, then Australia. The other group, accounting for 90% of the world's non-African population (some 5 billion people as of late 2006), took a northern route, eventually peopling most of Eurasia (largely displacing the aboriginals in southern India, Sri Lanka and Southeast Asia in the process), North Africa and the Americas. Wells also wrote and presented the PBS/National Geographic documentary of the same name. By analyzing DNA from people in all regions of the world, Wells has concluded that all humans alive today are descended from a single man who lived in Africa around 60,000 - 90,000 years ago, a man also known as Y-chromosomal Adam.
Since 2005, Wells has headed The Genographic Project, undertaken by the National Geographic Society, IBM, and the Waitt Family Foundation, which aims to creating a picture of how our ancestors populated the planet by analyzing DNA samples from around the world. He presents the knowledge gained from the project around the world, including at the 2007 Technology Entertainment and Design conference, where he spoke specifically about human diversity.
He is quoted as saying: "As often happens in science, technology has opened up a field to new ways of answering old questions...often providing startling answers."
As director of National Geographic Genographic Project he said this about the possibility of two Human species living today together: "We don't know how long it takes for hominids to fission off into separate species, but clearly they were separated for a very long time" This question may be estimated by comparing other species with similar speed of reproduction, media have own deductible methods.