Associated Press
NEW YORK -- Scientists who decoded the DNA of some southern Africans have found striking new evidence of the genetic diversity on that continent, and uncovered a surprise about the ancestry of Archbishop Desmond Tutu.
They found, for example, that any two Bushmen in their study who spoke different languages were more different genetically than a European compared to an Asian. That was true even if the Bushmen lived within walking distance of each other.
"If we really want to understand human diversity, we need to go to [southern] Africa and we need to study those people," said Stephan Schuster of Pennsylvania State University. He's an author of the study, which appears in today's issue of the journal Nature.
The study also found 1.3 million tiny variations that hadn't been observed before in any human DNA. That should help scientists sort out whether particular genes promote certain diseases or influence a person's response to medications.
The genetic diversity of Africa's population is no surprise to scientists. Modern humans evolved on that continent about 200,000 years ago and have lived there longer than anyplace else. The varied environments of Africa have also encouraged genetic differences.
The study focused on genomes, a person's complete collection of DNA. The researchers decoded genomes of a Kalahari Desert bushman and of Tutu, the 1984 Nobel Peace laureate and former head of the Anglican Church of Southern Africa. They also decoded partial genomes from three other Bushmen.
Tutu was included to represent a Bantu ancestry, in contrast to Bushmen. Bantu people have a tradition of farming, while Bushmen are longtime hunter-gatherers who represent the oldest known lineage of modern humans.
But when researchers looked at Tutu's genome, they found surprising evidence that his mother's ancestry includes at least one Bushman woman.
Tutu said that discovering he is related to "these wise people" made him feel "very privileged and blessed."
