http://genetics.plosjournals.org/archive/1553-7404/preprint/2006/pdf/10.1371_journal.pgen.0020143.eor.pdf

European Population Substructure: Clustering of Northern
and Southern Populations

PROVISIONAL ABSTRACT
The development of methodologies for defining population genetic structure has provided the ability to identify the major ethnic contributions in individual subjects in diverse populations. Using a genome-wide SNP panel we observe population structure in a diverse group of Europeans and European Americans. Under a variety of conditions and tests there is a consistent and reproducible distinction between "northern" and "southern" European population groups: most individual subjects with southern European ancestry (Italian, Spanish, Portuguese, and Greek) have >85% membership in the "south" population; and most northern, western, eastern and central Europeans have >90% in the "north" population group. Ashkenazi Jewish as well as Sephardic Jewish origin also showed >85% membership in the "south" population consistent with a later Mediterranean origin of these ethnic groups. Based on this work, we have developed a core set of informative SNP markers that can control for this partition in European population structure in a variety of clinical and genetic studies.


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in contrast with earlier western/eastern clusters

The people of northwestern Europe are largely descended from the Celtic and Germanic tribes. The people of southern Europe are largely descended from the Romans and Greeks.

These are four distinct ethnic groups, the progeny of four distinct waves of Indo-European migration into Europe over the course of two and a half millennia. Of course there has been considerable intermarriage over the subsequent two and a half millennia from commercial, political, and military mingling of the populations, not to mention the later influx of Slavic, Finno-Ugric, Turkish, and Moorish people.

Nonetheless, to discover that regional DNA markers can still be found that roughly correspond to ancient tribal boundaries does not seem remarkable.

The Races of Europe (http://snpa.nordish.net/racesofeurope.htm), by Carleton Coon (pronounced Cone)