Who's your Grand Daddy?

December 5, 2007

The Show

Who's your grand daddy?

(Click here to watch the video)

In our first segment, we take a look at home DNA testing kits. They're marketed as a great way to trace your ancestors and find out where your family came from. Some companies even suggest their tests could tell you whether you're related to Marie Antoinette or Ghengis Khan.

The reality is a little less exciting. Partly this is because the tests themselves can't always offer that level of precision. As Wendy Mesley reports, it's also it's because, in the big picture, everybody's DNA contains the same message: we all have roots in Africa.

December 5, 2007
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More information about the tests

The most common DNA ancestry test kits analyze two kinds of genetic material: mitochondrial DNA, which all people inherit from their mothers, and Y-chromosomes, which men inherit from their fathers. In both tests, the analysis compares the sample with a database of other samples and looks for features shared with those other samples. "Combo kits," which test both types of genetic material, are available for men, and usually cost more than the single-test variety.

Both tests look for haplotype group matches. Some haplotype groups are known to be associated with particular regions of the world. It is through these associations that the home testing kits aim to trace family histories.

December 5, 2007
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Links to more information (DNA genealogy)

Words like "haplotype" and "polymorphism" are fun to say, but even more so if you know what they mean. Wikipedia has a set of interesting primers:


Just last week, The New York Times published a feature about Henry Louis Gates Jr., the American scholar whose PBS special African American Lives helped popularize DNA ancestry testing. In the piece, Gates criticizes the current state of the industry.

A 2006 piece, also from the NYT, offers more background on the industry, including the ways some people hope to use test results for financial or educational advantage.

The Genographic Project is a partnership between National Geographic and IBM. The project sells test kits much like the ones offered by the private companies, performs similar analysis and provides similar results. The goal of the project is different, though: it aims to gather a large database of samples, for use in ongoing and future research, with the ultimate aim of learning more about human cultural and evolutionary history.

Finally, In November, Science magazine ran a detailed article about the science and business of genetic ancestry testing. It's a fascinating read, although a fee is required for access.

December 5, 2007
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