NatGeo climbs family tree to find roots

To generate public interest, Geographic is also offering a test kit that will allow anyone to take a swab of saliva and send it to a laboratory for DNA analysis. For assisting in the finances, participants will get a ‘‘personalized genetic analysis’’, a peek at their ‘‘deep ancestral history’’ — and assurances of total privacy.

The kits can be ordered at www3.nationalgeographic.com/genographic. Individual test results are expected to take about six weeks. Lest anyone be seeking proof that their ancestors came over on the Mayflower, National Geographic cautions that the test will ‘‘not provide names for your personal family tree or tell you where your great-grandparents lived’’. The society does promise, however, that everyone will get a genetic profile.

Most fossil evidence suggests that modern humans appeared in Africa between 100,000 and 200,000 years ago and began migrating to other continents about 60,000 years ago. Some scientists say there was a single migration, some say more. Asia, Europe and Australia were the next to be populated. The Americas were the last.

If scientists are right, all six billion people living on the planet today have ancestors who lived in Africa a long time ago. That concept has prompted some scientists to suggest that an African ‘‘Adam and Eve’’lie at the base of what is now a many-branched family tree.

‘‘We have some indications from prior studies about the migration of people in the last 50,000 to 10,000 years,’’ says Ajay Royyuru of IBM’s Computational Biology Center, which is collaborating on the project. ‘‘What’s missing is the detail, the ability for everyone on the planet to be able to see, understand, exactly how they got to be where they are.’’

Ten research centres around the world will receive funding from the Waitt Family Foundation to collect and analyse the DNA samples. Each individual is the result of the unique combination of their parents’ genetic code. But some genetic material, the Y chromosome and maternally inherited mitochondrial DNA, is passed to the generations essentially unchanged, except for rare natural mutations.

‘‘Once a marker appears by mutation in a man, all of his descendants will carry that,’’ Wells says. ‘‘If we compile information on a large set of markers and project them back in time using computer algorithms, the trail of mutations coalesces in a single Y-chromosome whose owner lived between 40,000 to 140,000 years ago in Africa.’’

Because of that mutation, named M94, is now carried by every man on the planet, Wells likes to call this man ‘‘Genetic Adam’’. But even he concedes the term may be misleading. —NYT