Inquiry & Impact

David Reich on migration, mixed ancestries, and ancient DNA

View of a pair of hands in a lab coat and gloves handling tubes labeled “DNA ONLY”

David Reich, professor of genetics at Harvard Medical School and of human evolutionary biology in Harvard’s Faculty of Arts and Sciences, explains how ancient DNA is rewriting what we thought we knew about human history. Drawing on more than 50,000 ancient and modern genomes his lab has studied, Reich shows that the people living in a place today are almost never the direct descendants of the people who lived there before — migration, mixture, and population turnover — are the rule across human history, not the exception. Reich argues that sweeping population mixtures — phenomena we typically associate with the last 500 years (as in the Americas) have deep parallels across Europe, South Asia, and Africa, uncovering connections between peoples that history and archaeology alone could never have revealed.

You Might Also Like
New economics building reaches its peak
A crane hoists a steel beam atop a building frame.

New economics building reaches its peak

The topping-off ceremony, a construction rite rooted in ancient Scandinavian rituals, took place August 27 at the site of the future Pritzker Hall, which will house the Department of Economics. The building project was set in motion five years ago.

How to build an evolutionary trap for viruses
M.D./Ph.D. student Vaibhav Mohanty, at left, with Eugene Shakhnovich, Roy G. Gordon Professor of Chemistry, used a chalkboard to illustrate their fitness landscape design (FLD).

How to build an evolutionary trap for viruses

Two Harvard scientists describe a way to engineer the evolutionary landscape that viruses experience, pushing them away from dangerous variants and into evolutionary dead ends.

New faces step to the front of the class
Snapshots from classrooms featuring professors Anna Russo, Tomer Schlank, and Mine Doğucu

New faces step to the front of the class

Amid the rhythms of the back-to-campus bustle, new faculty find themselves experiencing the same first-day excitement — and jitters. We dropped in on three, on the first day of their first classes.

David Reich on migration, mixed ancestries, and ancient DNA