Genetically, (Archbishop) Tutu serves as a poster child for southern African genetics, with a lineage primarily from the Sotho-Tswana and Nguni language groups—and a surprise ancestor discovered from the sequencing results. "With a single person, we pretty much covered the largest possible breadth of diversity," Schuster says. "At the same time, there was this amazing outcome in which we could also show Archbishop Tutu coming from the Bushmen, which was something he didn't know and was pleased to learn."

The original sequencing of the human genome a decade ago is now being widely extended. "Overall, I think the paper is a good example of how genome sequencing is rapidly becoming a ubiquitous tool," comments Jonathan Pritchard, a geneticst from the University of Chicago, who cited a study reported last week about sequencing the genome of a human who lived 4,000 years ago on the western coast of Greenland.

Sci. Am.