New Tool Tells You Where Your Ancestors Were 1,000 Years Ago

By Kendall K. Morgan

Scientists have devised what they say is the most accurate tool yet to trace your DNA back to the place where it was formed 1,000 years ago, in some cases down to the exact island or village. The tool, known as Geographic Population Structure (GPS), is available online for $29.99 through Prosapia Genetics. (You do need to have your DNA data available for upload. If, like me, you haven’t had your genome analyzed yet, you can order their kit, which covers 700,000 genetic markers, for $119.99.)

“What we have discovered is a way to find not where you were born — as you have that information on your passport — but where your DNA was formed up to 1,000 years ago by modeling these admixture processes,” said Eran Elhaik from the U.K.’s University of Sheffield in a press release. “What is remarkable is that we can do this so accurately that we can locate the village where your ancestors lived hundreds and hundreds of years ago — until now this has never been possible.”

The method developed by Elhaik together with Tatiana Tatarinova from the University of Southern California achieves accuracy by completely ignoring race and ethnicity to instead consider all populations as mixtures. According to their report published in Nature Communications, the new tool placed 83 percent of people correctly in their home country. When applied to 200 Sardinian villagers, GPS placed individuals within 50 kilometers of their native village. By comparison, previous methods to trace ancestry had an accuracy of about 700 kilometers for Europeans. For many non-European people, they often didn’t work well at all.

While genealogy and ancestry tracing is a popular hobby anyway, GPS might come in really handy for adoptees, missing children, or victims of human trafficking (in case you didn’t know, the trafficking of people across borders is a huge problem all over the world). The press release also noted that the tool could have some pretty big implications for personalized medicine. I was especially curious to know how exactly this information about our distant relatives could help us in that regard, so I contacted Elhaik by email to ask him.

He told me there are a growing number of prescription drugs known to work better or worse for people depending on where they come from. For example, he pointed out, people of African descent tend to need higher doses of warfarin to avoid blood clots than do Caucasian or Asian people. And Asian people tend to be more sensitive to platinum-containing chemotherapies.

“Clearly, knowing where one is from using genetic means would allow prescribing them the best medication for them, which is the whole philosophy behind personalized medicine,” he wrote.