Two studies have shown that, although genetic diversity in Europe is low, it is possible to determine which locations are in a European’s ancestry by examining his genome.
The geneticists working independently under John Novembre University of California, Los Angeles and Manfred Kayser at Erasmus University in Rotterdam used the same genetic samples, and examined about half a million single nucleotide polymorphisms in the samples, the 300,000 most reliable of which are then encoded using a two-dimensional distance metric. When the two dimensions are plotted as a graph, the metric consistently outlines a map corresponding to the geographical location. They report that when a political map of Europe is placed over the genetic map, 50% of plots end up within 310km of the country of origin and 90% are within 700k of the country of origin.
Greater genetic diversity was found in Southern Europe, less in Scandinavia and in the British Isles. This is consistent with the well established theory that Homo sapiens migrated to Europe as recently as 35,000 years ago, experienced a northern expansion from 17,000 years ago as the last Ice Age began to recede, and expanded further in the neolithic period 10,000 years ago enabled by the development of agriculture.
UPDATE: for those looking for a lucid and detailed outline of the paper, see this posting by Ed Yong on his “Not Exactly Rocket Science” blog.
- International Herald Tribune, 14 August, 2008: The genetic map of Europe
- New Scientist, 31 August, 2008: Human geography is mapped in the genes
- Correlation between Genetic and Geographic Structure in Europe .
- Current Biology , Volume 18 , Issue 16 , Pages 1241 – 1248
- O . Lao , T . Lu , M . Nothnagel , O . Junge , S . Freitag-Wolf , A . Caliebe , M . Balascakova , J . Bertranpetit , L . Bindoff , D . Comas
Genes mirror geography within Europe
John Novembre, Toby Johnson, Katarzyna Bryc, Zoltán Kutalik, Adam R. Boyko, Adam Auton, Amit Indap, Karen S. King, Sven Bergmann, Matthew R. Nelson, Matthew Stephens & Carlos D. Bustamante