Seeking Ancestry in DNA Ties Uncovered by Tests

Alan Moldawer's adopted twins, Matt and Andrew, had always thought of themselves as white. But when it came time for them to apply to college last year, Mr. Moldawer thought it might be worth investigating the origins of their slightly tan-tinted skin, with a new DNA kit that he had heard could determine an individual's genetic ancestry.

The results, designating the boys 9 percent Native American and 11 percent northern African, arrived too late for the admissions process. But Mr. Moldawer, a business executive in Silver Spring, Md., says they could be useful in obtaining financial aid.

Driving the pursuit of genetic bounty are start-up testing companies with names like DNA Tribes and Ethnoancestry. For $99 to $250, they promise to satisfy the human hunger to learn about one's origins — and sometimes much more. On its Web site, a leader in this cottage industry, DNA Print Genomics, once urged people to use it "whether your goal is to validate your eligibility for race-based college admissions or government entitlements."

I am a big fan of DNA testing, but I had never thought about these applications. Using DNA to "prove" you are 15% black or 2% Native American is an interesting use. But, I am not sure it really shows that. Lets say you have a black father and a white mother, like Barack Obama. The actual genes he inherits from his mother and father are determined by chance. So it is not at all clear that the test would show 50% African ancestory and 50% European ancestory. He might have ended up with more African DNA snippets that the test is looking for and fewer of the European ones. So it might say he is 75% African and 25% European, even if his father tests 100% African and his mother
100% European. I think these tests can give valuable information, but I don't think it gives the level of accuracy that people think it does when it says 83% West African, 10% British Isles, 7% Middle Eastern-North African.

via New York Times