[Galaico]

Originally Posted by PeterThaGreat

Races does exist, genetics prove that very well, in fact genetics prove that even Caucasoids have sub-branch: based on lates genomine DNA studies, the only typological system that makes biological sense, Caucasoids can splitted into a three. 1) Northern European 2), Sourthern European, 3) Middle-Eastern. As the studies progress we may probably get third one, a North-East European.

That's not completely true, as North Europeans and Southern Europeans cluster together versus Middle-Easterners:

there is low apparent diversity in Europe with the entire continent-wide samples only marginally more dispersed than single population samples elsewhere in the world.

Measuring European Population Stratification using Microarray Genotype Data

What actually means that Europeans are a tight homogeneous population.

In fact, the study that speaks about the cluster of South Europeans vs. North Europeans, European Population Substructure: Clustering of Northern and Southern Populations, only achieves to demonstrate such clusters when the markers are pre-selected, never when the markers are randomly selected:

As a measure of informativeness (i.e., the ability to distinguish populations based on genotypes), the informativeness for assignment (In) [31] was used to select smaller SNP marker sets that might be useful in assessing European population structure. We utilized a small subset of the original participants in order to select these markers, and their performance was then tested on the remaining dataset. Thus, the most informative 400 markers (included in Table S1), selected using 74 participants from Spain and 74 participants from western Europe, showed similar distinction of “southern” and “northern” population groups in Italian and SWD samples as did the original marker set (Figure 1C) (r2 correlation coefficient = 0.77, p <10> 0.01).

In contrast, random sets of 400 markers showed poor separation of the northern and southern populations (r2 values for all ten random sets of 400 were less than 0.1, p > 0.01).

Originally Posted by PeterThaGreat

As the studies progress we may probably get third one, a North-East European.

Actually in the latest study, Measuring European Population Stratification using Microarray Genotype Data (2007), we can see three or four main clusters:

At K=3 we can see a South Eastern cluster, a South Western cluster, and a North&Central cluster.

At K=4 we can see a South Eastern cluster, a South Western cluster, a North Eastern cluster, and a North&Central cluster heavily influenced by the North Eastern one and at a lower level by the SW one.

I know it's off-topic, but let me be a bit chauvinistic

The Spanish and Basque groups are the farthest away from other continental groups, which is consistent with the suggestion that the Iberian Peninsula holds the most ancient European genetic ancestry.