CVK
The latest issue of TIME Magazine has an article titled “Can DNA Reveal Your Roots?” about the growing numbers of people turning to DNA tests to find out about their ethnic heritage. The article points out that many of these testing companies are relying on insufficient data, and thus are probably providing faulty results. This is especially true for some companies that claim to be able to trace your ancestry back to a specific ethnic group in Africa:

Genetic testing has a special attraction for African Americans because most have no other way to trace their lineage; the slave trade did a thorough job of severing their African roots. Washington-based African Ancestry aims to re-establish these links by telling its customers whether their DNA matches that of any of hundreds of ethnic groups in Africa, from the Hausa in northern Nigeria to the Ashantis in Ghana. For Juanita Thompson, a real estate agent in Arlington, Va., the test had special significance because her mother had been adopted as an infant and her birth family was unknown. “There was always a void,” says Thompson, 61. “Having this DNA test gave me a connection to my mother’s side of the family. I feel good about finding another piece to the puzzle of who I am.”

As satisfying as it was for Thompson to be told that her mother’s family descended from the Yorubas in Ghana, it is exactly this kind of precision that has critics fuming. “I think it is a disgraceful thing to try to tell an African American that you can match them to any group in Africa now,” says Bruce Jackson, a geneticist at the University of Massachusetts at Lowell and co-director of the African-American DNA Roots Project, a nonprofit research group that is digging into the genetic history of American blacks. Jackson says making such classifications is premature because not enough people have been tested to establish distinct markers for each group. “Every ethnic group in Africa is a mix that we don’t understand yet,” says Jackson.

Rick Kittles, African Ancestry’s scientific director, defends his company’s work, saying he compares customers’ DNA with a database of more than 20,000 DNA samples from nearly 400 indigenous African groups. The company reports a match, he notes, only if the statistical probability is 90% or higher. “I’m doing the same thing everyone else is doing, but I am doing it on people of African descent, and I get criticized,” says Kittles, who adds that some 3,000 people have taken his $ 349 test.

These companies are starting to get celebrity clients. Oprah Winfrey, for example, recently took a test which told her she had Zulu roots. But skeptics question that claim since there is very little evidence linking Zulus to the North American slave trade.