Dan Vergano, USA TODAY7:30 a.m. EDT April 13, 2013
Gene kits that look for ancient ancestors can satisfy curiosity and help science at the same time, suggests the head of one prominent human gene-tracing effort.
“Everyone thinks there is a Cherokee princess hidden in their family history,” says genetic ancestry expert Spencer Wells. “And it turns out there almost never is one.”
Well that’s disappointing, but what genes are telling us about our ancestors is even more interesting, says Wells, the director of National Geographic’s Genographic Project. The first of a wave of public gene-charting endeavors, the project has recently unveiled the next phase of its efforts offering a story to us about human ancestry.
“Walking around today, we can see all sorts of different people. But how different are we really?” Wells asks. “It turns out the tools of genetics can answer that question, and so many more questions about how we populated the world over the last 60,000 years.”
How does he know? Well, the project, which started in 2005, had gathered DNA samples from more than 500,000 people worldwide, using $100 cheek-swabbing kits to analyze their genes.
Not without some controversy, the results are starting to affect science, playing a part in more than 35 published studies. A February report in the journal PLOS ONE for example, looked at genes in the Eastern Mediterranean, finding signs of the Islamic expansion there in the Middle Ages, as well as signs of a population there springing up 23,000 to 15,000 years ago that was distinct from Middle Easterners and Europeans. The study relied on comparison with worldwide gene samples collected by the project.
For ordinary folks buying the kits, what you get is a deep tour of time, starting in Africa more than 60,000 years ago, keyed to major groups of genes that show up in everyone’s ancestry. From these beginnings your genes track, in a sense, ancestral wanderings of groups of genes that point to past migrations tens of thousands of years in and out of Africa. “We all start off in Africa, that’s clear from the genes,” Wells says.
The results even indicate the extent of your genetic admixture with our ancient Neanderthal and “Denisovan” ancestors, cousin species to our own that disappear from the fossil record more than 30,000 years ago, after at least some mating with our forebears. Most people of non-African descent share what appears to be about 2% of their genes with Neanderthals, broadly speaking, based on studies of ancient DNA samples taken from bones found in caves.
“Everyone wants to know how much of a Neanderthal they are,” Wells says.
The Genographic Project released a newer gene “chip” for sampling roughly 500,000 gene “markers” in your genetic map late last year, facing newer entrants in the field, such as “ancestryDNA” from ancestry.com, which focuses on more recent genes and family connections, and 23andMe, which looks for disease-related gene markers. Such gene-ancestry analyses face criticism, with the Sense about Science charitable trust based in the United Kingdom releasing a report calling them “genetic astrology” in March, warning against reports linking people to “Vikings” or “Celts” or famous people such as Cleopatra. “What we can safely say is that we are all related to one another (including any famous person you care to name) and all have Anglo-Saxons, Vikings, Celts, Romans, you name it, in our family trees,” said genetics expert Turi King of the University of Leicester, in a statement released with the report.
National Geographic’s ‘Genographic Project’, a DNA ancestry tracing effort for humanity, has announced a new initiative to add more participants and more genes to its map of human origins. Here, a Chadean man from the Saharan Desert recorded on a project expedition. Nat. Geo. – David Evans
On the other hand, scientific sleuths warned in a January report in the journal Science that they were able to identify about 12% of the men they investigated in a genetic registry using genes from ancestry sites to circle in on their last names and locations. The authors wanted to raise people’s awareness of privacy issues raised by entering their genes into public ancestry registries.
Although results are kept confidential, issues of privacy have also been raised about the Genographic Project among Native Americans and other indigenous groups. Some of those concerns have been assuaged worldwide by the Genographic Legacy Fund, which since 2006 has started more than 60 projects worldwide to help local communities preserve languages, artifacts and cultural practices. The fund is supported by and paid for by the ancestry kits that the project sells to people wanting to find out about their ancestral genes.
For his part, Wells is dismissive of attempts to link specific genetic “sweeps” seen in human genes to relatively recent events in human history such as the Black Death of the 1400s or Genghis Khan. But he argues that clusters of genes indicating deeper moments in time, like migrations into Europe after the Ice Age, look reasonable from a scientific perspective to point to in people’s genetic makeup.
“Here is a chance for everyone to take part in a great scientific endeavor,” Wells says. “We really are at the beginning of a new era in looking at our ancestry using genetics, and we are finding out a lot from the thousands and thousands of people participating.”