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3 Degrees of Separation: Genetic Connectivity

Steve Williams · Thursday, December 13th 2012 at 2:45PM · 1473 views
Genealogy Team May 30, 2012

When we learn about our ancestors, who they were and where they came from, the discoveries become part of how we define ourselves and how we understand ourselves to be unique. The PBS series Finding Your Roots has taken this a step further, showing us how much we share with others and how interconnected our stories are.

This has been a theme of the 10-part series, something that the show’s host, Professor Henry Louis Gates, Jr., has returned to again and again — that despite our differences, whether racial or cultural, Americans are more interconnected than we know.

It isn’t just that our stories share parallels, but that the connections run deep and can be seen in our DNA. It’s an irony that as the world’s population has grown exponentially in the last 500 years — from about half a billion to now seven billion — we are actually closer and more connected.

During the filming of the show, Professor Gates visited 23andMe and talked to scientists Mike Macpherson and Joanna Mountain, both of whom served as consultants to the show. At one point Macpherson taped up photographs of the roughly two-dozen guests who appeared in Finding Your Roots onto a whiteboard. Then he sketched out the genetic connections that linked this seemingly random collection of people.

This was the first time that someone had demonstrated the genetic connectivity of any two people on earth. Macpherson was able to make some surprising links that connected, for example, Martha Stewart to Samuel L. Jackson, and Barbara Walters to the Imam Yasir Qadhi.

Unlike previous examples that relied on social connections — friends of friends of friends — this connection is through cousins matched within a genetic database of over 150,000 people.

This wasn’t just a parlor game. Indeed that notion that any two people — a cop in New York and a street vendor in Mumbai, say — could be connected through five other people was first written about by Stanley Milgrim from experiments he did in the late 1960s. It’s a little more complicated than what Milgrim theorized but he got the gist right.

These previous theories of connectivity focused on social connections; the idea that we are all — all seven billion of us — linked to each other by six degrees of separation. This theory of connectivity even spawned a game named after one of Gates’ guests, “Six Degrees of Kevin Bacon.” The game links any actor to Kevin Bacon by five other performers. Bacon — whose wife Kyra Sedgewick was also on the show — said for a long time he hated that his name was the punchline for a joke. But he has since embraced it and is using the idea of social connections to link people to worthy causes.

More recently Facebook and LinkedIn have shown that just four “connections” could link any two people together.

Macpherson connected the Finding Your Roots guests via a much shorter genetic chain. Any two people are connected through just one or two other individuals.

Why is this a revelation?

It’s new because this isn’t the notion that you are connected to someone else because of who you know. It’s the notion that you are connected to someone because of who you are related to.

People are no longer isolated by geography and so the differences between people are smaller than in the past.

Perhaps in no other place has the convergence of people of different cultures and histories been as dramatic as the Americas. And while the clash of cultures and histories has been both painful and brutal at times, it is what forged our history more than anything else, Gates argues.

“I’ve always thought that it was that story of America,” said political commentator Linda Chavez in the last episode of the Finding Your Roots series.

People came here from all over the world, some voluntary and some involuntary, and mixed, she said, “and that’s made us stronger.”


About the Authors:

Joanna Mountain is a geneticist who is a consultant to the PBS series “Finding Your Roots,” and consulted previously on the PBS series “Faces of America.” Dr. Mountain completed her PhD in Genetics at Stanford University and has spent over 20 years studying human genetic diversity. Currently, she is Senior Director of Research at 23andMe, Inc.

Scott Hadly is a writer with extensive experience as an investigative reporter. Currently Mr. Hadly is Content Editor at 23andMe, Inc.

http://www.pbs.org/wnet/finding-your-roots...
3 Degrees of Separation: Genetic Connectivity

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Steve Williams Coatesville, PA

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Comments (8)

Steve Williams Thursday, December 13th 2012 at 3:17PM

Did you see the series Irma? Has anyone posted about it before? I will be watching it online as of course I don't even have a TV. Well I do, but no cable service to connect it to.

Steve Williams Thursday, December 13th 2012 at 3:29PM

And it is interesting how I found out about this show, and how it illustrates the benefit of positive dialog. I went from Siebra's post on C. L. Bryant and found a story about Kevin Bacon being married to his cousin and thence to this site.

powell robert Friday, December 14th 2012 at 9:03AM


thank you again Steve --myBrother and fellowAmerican-----for the SuperReading

"the convergence of people of different cultures and histories been as dramatic as the Americas. And while the clash of cultures and histories has been both painful and brutal at times, it is what forged our history more than anything else"

Steve Williams Friday, December 14th 2012 at 12:30PM

And Robert, in our Making of Current American History , it still is painful and brutal. As an example, I have not commented on Maurice's blog because he has said, no WHITES allowed in his group, so I figure no WHITES allowed on his blog. And though I don't call myself WHITE, he surely would, and after watching his video up to the point where he starts YELLING about WHITES, I had to stop, too much HATRED there.

Steve Williams Friday, December 14th 2012 at 12:36PM

I can deal with Harry, no matter the name calling and slurs and inability to adapt, misplacement of the problem, and misapprehension of the solution.

Steve Williams Friday, December 14th 2012 at 12:44PM

I believe Henry Louis Gates has done a great service with his series, in spite of the White/Black language. I'm about 2/3 thirds of the way though the episodes. If you do watch this series, if you have not already, just be aware the episodes are listed in reverse order.

ROBINSON IRMA Thursday, April 10th 2014 at 6:47PM

@STEVE, SO GLAD YOU DON'T WORRY ABOUT BEING PUT ON THE CONSERVATIVE IT LIST OF THOSE WHO DARE TO ACCEPT ANY THING SCIENTIFIC...YOU KNOW FULL WELL THE EARTH IS FLST (OTFL) (SMILE)


ROBINSON IRMA Thursday, April 10th 2014 at 6:47PM

YES, I HAVE WATCHED IT AND YES SIEBRA DID INTRODUCE ME TO THIS PROGRAM VIA ONE OF HER POSTINGS...

MY ONLY PROBLEM IS , I MISS MOST OT THESE PROGRAMS SINCE THEY ARE LISTED WHEN TEHY WILL BE ON ON PBS, BUT THEN WHEN YOU GO THERE THEY ARE OLDING THEIR FUND RAISERS.(SMILE)

THEY DO HAVE SOMETING SIMILUR ON TEH SCIENCE CHANNEL THOUGHT...

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