Tracing Your Ancestry to Africa
DNA databases claim to allow people to trace their origins, but critics say the science is too imprecise to be valid
By Herb Frazier
Barbara Morrison-Rodriguez took three DNA tests in the past five years before African Ancestry in Washington, D.C., identified a genetic link between her and the Mende people.
Other tests did not find any matches to other African ethnic groups because of the limited size of the companies’ DNA databases, she says. “I wanted to know: What country, what tribe? That is what African Ancestry was able to tell me,” says Morrison-Rodriguez, a former faculty member at the University of South Carolina.
Geneticists can compare DNA, the substance in human cells that contains genetic information from an individual’s ancestors, to determine a person’s origin when written records lead to a genealogical dead end.
African Ancestry says it usually can trace at least one family bloodline to a specific region of Africa. It is that claim, however, that has skeptics wondering whether the company has acknowledged all of the flaws in an imprecise science.
The test to collect Morrison-Rodriguez’s DNA was painless and simple. She was sent a kit containing a cotton swab to remove buccal cells from the inside of her cheek. After mailing the kit back to African Ancestry, the company extracted DNA from the cells and compared it to its database of about 22,000 DNA samples.
Gina Paige, African Ancestry’s president, said the company’s DNA database contains genetic information from 30 African nations and includes 135 ethnic groups. The company created its database from genetic sequences of African tribes published in scientific literature. It also has collected DNA samples from volunteers in Africa.
For $349, African Ancestry tracks a person’s maternal or paternal lineage. For an additional $241, the company will test both sides of an individual’s bloodline.
The maternal side is the realm of mitochondrial DNA, a strand of genetic material found outside the cell nucleus and apart from regular genes. Mitochondrial DNA is passed only from mother to child. Mothers can pass it to their sons, but the sons can’t pass it to their offspring. When the maternal lineage of contemporary people is compared, scientists believe that they all can be linked to a common ancestor who lived in Africa about 100,000 years ago.
