Can DNA Reveal Your Roots?

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.

One of the less controversial aspects of genetic genealogy is its ability to help people fill in gaps in their family tree. Leo Little, a retired engineer in Austin, Texas, had used historical records to trace his lineage back to his great-great-grandfather Thomas Little, who was born in Alabama in 1816. Then, he says, "I hit a brick wall. I knew my Littles were from the South, but there were a lot of Littles from the South, and it was impossible to sort out." After he took a DNA test from Family Tree DNA, he began leading one of the company's 1,900 surname projects, in this case checking test results on Littles. As a result, he has identified three distant cousins. By pooling their family records, the cousins have been able to trace their roots all the way back to 1680.

While members of the Little family were happy to share genetic information, some people worry about unauthorized sharing. DNA-test companies say they will keep results confidential, but at least one, DNAPrint, requires customers to sign a consent form acknowledging that results "may be subpoenaed by court order." Another complaint is that some of the most common tests reveal only a sliver of ancestry. The Y-chromosome test, for example, traces only the patrilineal line (your father's father's father and so on, but not your father's mother). Similarly, the mitochondrial-DNA test, which looks at DNA passed from the mother's egg to both her male and female children, illuminates only your mother's female ancestry. "If you go back 300 years, you have more than 1,000 ancestors. They are telling you about 1 in 1,000 of your ancestors. I think they should make that clear," says Stanford ethicist Greely.

Those flaws haven't deterred amateur genealogists like Charles Kerchner of Emmaus, Pa. The retired electrical engineer says he has spent about $3,000 testing himself and nine distant cousins in order to confirm relations that historical records had already indicated. Was it worth it? "Absolutely. It is like a high-tech Bible entry," says Kerchner, referring to the tradition of recording names and birth dates in family Bibles. Using historical records, he has been able to trace his roots back to Switzerland and Germany in the early 1500s. But Kerchner, 60, says he will not rest until he finds a German ancestral village where he can sit down someday and have a beer--hopefully with a local member of his clan. Having exhausted the paper trail, he says, "my only hope left is DNA testing."