Humanity’s descent is looking less like the linear succession it’s often thought to be and more like something resembling an ancient mosh pit.
The last decade’s revolution in our ability to read ancient DNA has transformed our understanding of humankind’s roots, settling long-running debates among scientists about who is related to whom, and creating a swirling picture of human ancestry in which groups regularly immigrate, emigrate, colonize, conquer, and disappear, exchanging genes, languages, and cultures whose traces still exist.
Traditionally, scientists have inferred relationships by comparing morphological traits from remains found in different parts of the world. With the advent and expansion of DNA technology, we are increasingly discovering not just what people looked like in a particular region over time, but who bred with whom and where they originated. In Europe, for example, groups whose remains have been found in the archeological record turn out to have made little contribution to the gene pool of modern Europeans.
“New groups arrived in Europe after the advent of farming. Europe is a dynamic place,” said John Hawks, the Vilas-Borghesi Distinguished Achievement Professor of Anthropology at the University of Wisconsin-Madison. “Europe has undergone a succession of colonization by other populations.”
Hawks spoke at the Radcliffe Institute for Advanced Study’s Knafel Center last Friday. He was one of the speakers at the institute’s annual science symposium, this year focused on “The Past, Present, and Future of DNA.” The session featured discussions related to modern DNA analysis, including the possible resurrection of extinct animals like the mammoth, forensic DNA investigation, the ethics of DNA, and a peek at the likely future of DNA science.
Radcliffe Dean Lizabeth Cohen, the Howard Mumford Jones Professor of American Studies, introduced the event, saying that science is in the institute’s own DNA, going back to Radcliffe College’s Bunting Institute (named after Mary Ingraham Bunting, former Radcliffe president and microbiologist). DNA, Cohen said, has fascinated and challenged scientists since it was first isolated in 1869. Since then, she said, advances in DNA technology have transformed an increasing number of fields, even history.
Janet Rich-Edwards, co-director of Radcliffe’s science program and associate professor at Harvard Medical School and the Harvard T.H. Chan School of Public Health, compared the impact of modern DNA science with the moon landings. And, as transformative as the impact of DNA technology has been already, its future is rife with possibility, as scientists devise ways to edit the genome, create artificial DNA, and engage in large-scale environmental DNA sampling, providing new ways to understand the environment and what inhabits it.