The largest genetic study of African populations reveals a greater diversity among the continent's cultural groups than previously known....the new research shows that "no single African population is representative of the diversity of the continent," says study coauthor Sarah Tishkoff of the University of Pennsylvania in Philadelphia.
Tishkoff and her colleagues analyzed particular DNA sequences... from more than 3000 people from 121 different populations scattered throughout Africa....
To reach remote groups, such as the Pygmies of Cameroon and the hunter-gatherers of Tanzania, researchers drove off-road and set up makeshift labs with equipment powered by their car battery.
"This is by far the most in-depth analysis in terms of populations analyzed," comments evolutionary geneticist Mark Stoneking of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.
..."We knew that African populations were diverse in culture, art, religious ideas," says Roy King of Stanford University School of Medicine. "Now we see that genetic diversity goes along these same lines"....
It turns out that the San bushmen of southern Africa have the most distinct, and therefore oldest, genetic sequences, the team reports....
Genetic information from African-Americans living in three U.S. cities and an additional state was also collected and analyzed. On average, African-Americans inherited 71 percent of their DNA from western Africa, 8 percent from other locations in Africa and 13 percent from Europe, the team says. Most of the African-Americans in the study had mixed ancestry from different regions of western Africa, which made tracing ancestry to particular ethnic groups difficult....
The researchers are quick to point out that the data set is incomplete. "We analyzed 121 populations out of a possible 2000," Tishkoff says....
--Science News, article by Solmaz Barazesh, 23 May 2009
