National Geographic Explorer-in-Residence Dr. Spencer Wells took Concord Academy on a journey through some of the most remote regions of the world Thursday, as he explained the Genographic Project that he directs and the secrets of human migration patterns that the project has discovered.
“People are so different,” said Dr. Wells, a population geneticist. “But how different are we really?” Despite obvious physical variations, humans, when compared genetically, are virtually identical to one another, he said. In fact, all humans alive today share a common ancestor who lived as recently as 2,000 generations ago. “We’re all 99.9 percent identical, and we’re all effectively members of an extended African family,” Dr. Wells said.
Family trees trace lineage through genealogy, but typically go back a few generations at most. Genetic analysis can trace a family back thousands of years. National Geographic and IBM’s Genographic Project has collected DNA from hundreds of thousands of people around the world, including average Americans and indigenous residents of villages that are far removed from modern society. By studying patterns of genetic variation, the project is unraveling a story of interconnectivity among all humans. It is also attempting to slow or halt what Dr. Wells’ called our current “period of cultural mass extinction” by funding various programs in indigenous regions around the world through the Genographic Legacy Fund.
Dr. Wells’ lecture—which he presented for CA parents, alumnae/i, and the public the night before—demonstrated the migration patterns which took humans from Africa to every corner of the earth. Describing the vast, inhospitable Sahara Desert, he posed the question of how people in southern Africa could cross that sandy expanse and reach the Middle East and beyond. The answer: the earth underwent substantial climactic change, as it does every 20,000 to 22,000 years because of the nature of the earth’s rotation. Extremes of the rotation bring extreme weather, and pushed African monsoons northward. “The Sahara used to be grassland,” he said, explaining that it was not only passable but inhabitable.
Dr. Wells predicts that natural climactic changes, which he said humans are exacerbating, will be the main determinant of migration patterns in coming years, just as they were thousands of years ago. A case in point, he said, was Hurricane Katrina, which displaced about a million people, many of whom did not return.
The presentation explained the convergence of science and history in the Genographic Project, and the ambitious, broad spectrum of people it has reached. Last year alone, Dr. Wells traveled to twenty-eight countries.
After his presentation, the scientist visited with several biology and advanced biology classes. When a student asked what was most important about his work, he replied, “the social message that we’re all extended cousins.”
But race, he warned, has sociological and environmental components; it is more than DNA. “The DNA shows that we’re all the same, but if you’ve grown up African American, you know what it’s like to be discriminated against,” he said. “Changing social norms is much more difficult.”
Dr. Wells’s visit was made possible through Concord Academy’s Hall Fellowship, which honors former Headmistress Elizabeth B. Hall (1949–63) by inviting distinguished lecturers to campus every year.
To learn more about the Genographic Project, visit nationalgeographic.com/genographic.