David Reich studies DNA and human population structures to make discoveries at the interface of biology and anthropology. Reich and his team combine their skills in molecular biology, computer science, math, bioarchaeology, and genetics to generate large-scale data from ancient DNA, which they mine to gain insights about human biology and disease. A major focus of their work has been the population genetics of risk factors for certain diseases. The team has also developed methods for analyzing data from modern and ancient DNA to learn about changing population structure and admixture events over time and to better understand the impact of selection on human evolution.
Analyzing DNA from the remains of hundreds of ancient humans across West Asia, the Balkans, Greece, present-day Turkey, and other regions, scientists have revealed surprising migrations that illuminate human history and led to the languages billions of people speak today. Scientists have found DNA evidence for the southward migration of the people who spread the so-called Clovis culture of North America. But starting about 9,000 years ago, these people were replaced by a distinct population. Fueled by advances in analyzing DNA from the bones of ancient humans, scientists have dramatically expanded the number of samples studied­­ – revealing vast and surprising migrations and genetic mixing of populations in our prehistoric past. A new analysis of genome sequences from the ancient Minoans and Mycenaeans by HHMI Investigator David Reich and colleagues offers insight into the origins of these Bronze Age cultures. Analyses of ancient DNA from prehistoric humans paint a picture of dramatic population change in Europe from 45,000 to 7,000 years ago. New studies provide the first genetic evidence that humans interbred with Neanderthals in Europe. HHMI scientists have shown that previously unrecognized groups contributed to the genetic mix now present in most modern-day Europeans. By studying which genes modern humans still retain from our Neanderthal ancestors, researchers are able to tell a clearer story about the biological impact of human-Neanderthal interbreeding.