According to geneticists who developed the map, it shows populations in Europe are similar, but not too close to tell them apart genetically. The Times reports that one of those scientists says it should be possible to create a test that can tell you which European country youre probably from.
Thatd be great. Right now, DNA tests can give you a haplogroup or a general population (for example, East Asian or Indo-European), but they cant specifically tell you which countries your DNA represents.
The outlines on Europes genetic map resemble those on its geographic map. The most genetic difference occurs between northern and southern populations, probably reflecting ancient migrations that populated Europe from the south.
The map also shows where two genetic barriers arose: One separated the Finns from the rest of Europe due to the small early Finnish population; the other separated those in Italy, perhaps because the Alps kept people from moving back and forth.
The map came from genetics testing that analyzed 500,000 sites on the human genomes of nearly 2,500 Europeans.