Rebuilding The Family Tree

Lesley Stahl Reports On The Hopes And Limitations Of Genetic Genealogy

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In fact, he embraced it, and extended an invitation to Vy for Thanksgiving dinner in Poplar Bluff, Mo. "And I thought it was really very charming and very nice. But I wasn't going to Missouri," Vy remembers, laughing.

Not on Thanksgiving, but she did go to Missouri. Marion drove two and a half hours to the airport to meet her and her daughter.

"And he grabs us, throws his arms around us. And he said, 'This is a day I have prayed for. I'm so glad you came. Thank you,'" Vy remembers.

"I grabbed her and hugged her, said, 'You're part of my blood. You're mine--cousins, God's put us together.' Exactly what I told her," Marion remembers.

"When you started this, in your wildest imagination, did you ever think you'd end up in a white family?" Stahl asks Vy.

"No," she replies.

Asked if it's funny, bemusing or weird, Vy, says, "All of it. …But there's some joy in the discovery. Who am I? Why do I look the way I do? It's like discovering American history through yourself."

The American history Vy discovered is a common one it turns out. Geneticist Rick Kittles runs a company called African Ancestry that specializes in DNA testing for black Americans. He says a full one third of the men he tests find out they have a white male relative somewhere back in time.

How do people who find this out react?

"Some black men get upset and say, 'Look, I'm black. Look at me, I'm black.' And you know and I say, 'Yeah, you are. But this small segment of your DNA doesn't go back to Africa but to Europe,'" Kittles says. "We are a mosaic of many different ancestors. We can go back several generations and there are hundreds of people who, thousands of people who actually contributed to our DNA."

And that's the rub. This business of genetic genealogy is fraught with limitations. For one thing, it can only provide information about a tiny fraction of our ancestry. Because we get half our DNA from our mothers and half from our fathers, almost all of our DNA gets shuffled and remixed every generation, making it impossible to trace what comes from whom. There are just two bits of DNA that remain pure - the "Y" chromosome, which passes directly from father to son, and something called mitochondrial DNA, which passes unchanged from mother to child.

Hank Greely, a law professor at Stanford University, has studied this new field. He worries that people don't realize just how many ancestors they actually have.

"Eight generations ago both you and I had 256 great-great-great-great-great-great grandparents," Greely points out. "It doubles every generation. So you've got two parents. You have four grandparents. You have eight great grandparents. Sixteen great-great grandparents. And it adds up fast. It adds up so fast in fact that if you go back 20 generations you've got over a million grandparents."

1,048,576 to be exact. And in each generation, DNA testing can provide information about only two of them.

"So you could be Peruvian on your mother's mother's mother's side, Japanese on your father's father's father's side. Swedish on everything else," Greely explains.

"And you'll never know?" Stahl asks.

"And you'll never know the Swedish from the 'Y' chromosome or the mitochondrial DNA," Greely says.

"We don't oversell. I mean, we just say, 'Look, we provide a service.' If you're interested in exploring a tiny bit of your DNA and trace it's ancestry we can do that," Kittles says.

"When you say it's a tiny little amount…," Stahl says.

"It's less than point one percent," Kittles explains.

"That's pretty teeny," Stahl remarks.

"Yeah, but for people who know nothing about any of them, I think it's very important," Kittles says.

Kittles' company has amassed the largest database of DNA sequences from countries in Africa, particularly those from which slaves were taken. His goal is to help American blacks trace their ancestry back to Africa, a history totally lost to them.

To Vy Higgensen, the prospect of tracing even a tiny fraction of her ancestry back to Africa was enthralling. 60 Minutes sent her DNA to African Ancestry, as well as several other genetic genealogy companies, to see what they could tell us about Vy's maternal lineage.