Back To Africa

dna genetic journey africa asia generic CBS/iStockphoto

By CBSNews.com's Stephen Smith


To hear my parents tell it, my ancestral cocktail breaks down like this: two parts British, one part German, and one part French. (One of my distant grand-pėres worked for Lafayette as a mercenary).

But Dr. Spencer Wells, a geneticist who has seen my DNA results, offers a much different perspective: He says I have a Y chromosome with a marker called M-343. "This," he says with scientific confidence, "defines the R1b lineage."

R1b? So, is that English, German or French?

According to Wells, I'm a lot more worldly than my parents would have me believe. In fact, based on one DNA cheek swab, he tells me exactly how my ancestors migrated across the globe over tens of thousands of years to get me where I am today.

Wells is the brain trust behind the Genographic Project - a five-year effort to map the journey of humankind. The project, spearheaded by National Geographic and IBM, aims to take more than 100,000 DNA samples - from both indigenous communities and the general public - in order to trace the path of our ancestors.

"We see a chance to write the genetic history of our species," Wells says.

The genetic history of my ancestors, the so-called R1b lineage, turns out to be quite a long and winding one. Genetically speaking, R1b is type of haplogroup - a series of genetic markers that I share with other men who carry the same random mutations. As an R1b guy, my immediate ancestors do indeed hail from Western Europe. But that was just the last stop on a long journey.

In a nutshell, Wells says, my ancestors' migration goes something like this: They started in Africa roughly 50,000 years, when they embarked on a risky exodus to the Middle East. From there, they ventured westward along the step lands of central Asia. During this leg of the journey, they became skilled hunters and lived off woolly mammoth. When my ancestors, aka the Cro-Magnon, traveled farther west, some 16,000 years ago, they sat out the worst part of the last Ice Age and retreated to the warmer confines of the Mediterranean. Only when the ice melted did they finally settle in Western Europe.

"They brought with them art and fully modern technology and actually took over Europe from the Neanderthals," Wells tells me.

My cave-painting, tech-savvy ancestors thrived. Today, R1b (which is scientific shorthand similar to a car model) is prevalent throughout Western Europe; up to 90% of Spanish men and 95% of Irish men carry it but only 5% do in the Middle East. (Take an interactive genetic journey).

To get a sampling that can yield a representative analysis, the Genographic Project not only solicits DNA samples from people like me, they also employ 10 scientists to cull data from indigenous communities around the globe - from Paris to Shanghai to Melbourne.

  • Stephen Smith

    Stephen Smith is a senior editor for CBSNews.com

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