Science is reporting, “Genography” puts European ancestry on the map, on recent research out of the University of California.
Population geneticist, John Novembre (cool name, btw), plotted the genetic fingerprints of 1300+ Europeans on a map and found that our DNA provided a “sort of global positioning system” for where your genes originated. Check out the map that accompanies the article, it vaguely looks like the continent of Europe.
Now they had a highly prejudicial sample population, specifically that each person tested was clearly associated (through to their grandparents) to a specific region. So the likelihood that “foreign” DNA wouldn’t likely be introduced for several generations but still an interesting process. This process could simply look at your DNA and not only tell you that you were from Switzerland but likely what village or set of villages you came from.