An international group of scientists has shown that genetic analysis can pinpoint Europeans’ geographic origins within a few hundred kilometers. The scientists mathematically mapped the differences between people’s genomes onto a two-dimensional grid, and the result looked much like a map of Europe.

John Novembre, an evolutionary geneticist at the University of California, Los Angeles, who participated in the study, says that the findings could have research implications. Scientists can study a disease by looking for genetic variations shared by people who suffer from it. But test subjects from different countries may have unrelated genetic variations that yield false positives. The same technique that produced the genetic map could filter out such regional differences, making it easier to home in on variations of interest.

Blood will out: A mathematical operation maps (right) the most significant differences between the genomes of 1,387 Europeans onto a single axis (PC1). Performed again, the operation maps the most significant differences that the first iteration missed (PC2). The result–a 2-D map of genetic variation–looks remarka­bly like a map of Europe (left).