With a quick swab of the inside of your cheek, genetic researchers can determine where your people roamed 100,000 years ago.
Did your folks take the southern route out of Africa, through Australia maybe? Or did they walk north during an ice age, across what is now sea, to trek across Southern Europe? Into Asia and India?
The Genographic Project aims to trace our matrilineal history all the way back to what’s called “Mitochondrial Eve,” the mother of us all.
A string of 569 letters, the DNA sequence tracing your genetic lineage on your mother’s side, reveals where a mutation — a random, natural change — occurred.
I can’t grasp the DNA science enough to explain it, and the TV special really should be clearer about how geneticists determine the timing of generational changes. But I am fascinated by the film exploring the idea, airing Sunday on National Geographic Channel.
Geneticists globally have been using the “markers” from inside people’s cheeks to construct “one giant mitochondrial family tree,” as the film puts it. Every cheek tells a story.
I tried it, and I’m proud to say I’m a member of the subset of Haplogroup U. Where’s the family reunion?
“The Human Family Tree,” a thoroughly engaging film narrated by Kevin Bacon, proves we’re all only six or so degrees separated from each other. “Human Family Tree” opens at a street fair in Queens, N.Y., where an ethnically diverse crowd mingles.
They swab, as we try to follow the science that determines the age and geographic spread of each branch of the family tree.
Queens was happy hunting for geneticist Spencer Wells, who found the crowd was carrying genetic markers for virtually all the major human migrations that eventually spread across the continents.
The point is, “regardless of race, nationality or religion, all of us can trace our ancient origin back to the cradle of humanity, East Africa.” It’s been 60,000 years since we took off from Mother Africa — and are our feet tired.
For the past four years, Wells and his colleagues at National Geographic and IBM’s Genographic Project have globe-trotted to collect DNA in cheek swabs and blood samples from hundreds of indigenous groups. By comparing the DNA, the project retraces the ancient history of human migrations since our species got going in Africa 200,000 years ago.
The results hold surprises for many of the participants.
Dave Reed, an African- American featured in the special, was sure his ancestors came from Ghana. Reed’s DNA results found that, like many people of the African slave diaspora, his Y chromosome shows a European and Central Asian lineage. We learn that Dave’s genetic lineage is true of around 30 percent of African-Americans, revealing the complex history of the slave-trading era.
Another participant, Mehmet Demirci, gets an equal eye-opener: As a Muslim, Mehmet is surprised to learn his haplogroup is J1, which is largely a European Ashkenazi Jewish group.
(My own stunner was the revelation of my maternal ancestors’ schlep to Northern Europe. I would have guessed my mitochondrial lineage was more frequent in Russia than Finland.)
It’s all overwhelming to think about. Some viewers won’t buy the premise. Some may argue with the broad assumptions and speculation. Others may challenge the science.
For those who buy in, it’s possible to do your own cheek swab and get the results back from the Genographic Project for $100. It’s done anonymously and takes about six weeks, according to the website.
The film flows easily between maps, re-creations, interviews in Queens and explanations from Wells, all pointing to our ultimate connectedness. Cue “It’s a Small World After All.”
Scientists believe humans were on the verge of extinction at one time, but came back because “we got smarter,” coming up with language, for instance.
“In terms of the initial population in Africa,” Wells says, “it turns out that if we look at the pattern of generic variation across the whole genome, probably as few as 2,000 people were alive 70,000 years ago.”
Parking was easier then.
Joanne Ostrow: 303-954-1830 or jostrow@denverpost.com
