DNA Collector

Scientist Sarah Tishkoff pulls together a database of African populations—one DNA sample at a time.
April 2009

“Africa is one of the most genetically diverse regions of the world,” observes scientist Sarah Tishkoff. “It’s thought to be the site of origin of modern humans. So if we want to learn more about human evolution, we need to be looking amongst African populations.” 

Tishkoff is the David and Lyn Silfen University Associate Professor with appointments in the genetics department in the School of Medicine and the biology department in the School of Arts and Sciences. To explore the continent’s genetic complexity, Tishkoff ventures across savanna and forest collecting DNA samples from a cross-section of Africa’s many ethnic groups. She receives considerable assistance in the field from graduate students like Jibril Hirbo and postdoc Alessia Ranciaro.

Using the genetic database they are building up, Tishkoff has thrown light onto human origins and migration out of Africa; the population history—and prehistory—of peoples within Africa; the genetic basis of resistance to infectious diseases such as malaria; and much more. In this slide show, Tishkoff discusses findings related to genetic mutations in African pastoral populations who evolved the ability to digest milk as recently as 3,000 years ago.