` ::Ah, I've just noticed it is the second sample set, they do not give the composition of the population here, but they do state For a substantial portion of this set, European country of origin was available as was a record of the four-grandparental country of origin. So I think that is cleared up.  I think there are several important points to make here. # Wikipedia does not publish original thought. The papers describing the SNP data are not intended, nor are studies designed, to infer ancestry. These papers do not address the origins of the populations mentioned. These are involved in biomedical research, they are looking for structure within populations. Indeed the Seldin paper makes no claims whatsoever regarding the oigins of populations, it has a somewhat vague reference to neolithic contributions to southern Europe. We cannot make reference to what we think the papers imply, only to what the papers own conclusions are. # We would not necessarily expect to see a strong specific correlation between Iberian people and Irish people per se, even if we accept that the Irish/British population is descended primarily from a south western Ice Age refuge. We need to put it into perspective. If we assume that there were indeed three refugia, we must assume that the populations of these were only seperated from each other for about 10,000 years (say 23,000 ya to about 13,000 ya), and we do not know the degree of population exchange between these refugia during this time, were they completely independent? So this is a relatively short period of time, certainly not enough for major changes to be discernable between the various populations. We see the difference in Y-chromosome (and indeed in mtDNA) data simply because these markers are more prone to suffer from bottleneck and genetic drift. They exagerate the difference, but if they didn't we would not be able to detect it at all. # The north south structure seen by Seldin, Dupanloup and Bauchet may due to a larger neolithic component in the south of Europe relative to the north of Europe. If we assume that this is the case, then we would certainly expect to se a big difference between south and north. Let's look at it logically. The paleolithic population of Europe was probably very homogeneous during the mesolithic, probably being descended in totality (or at least in the main) from a small(ish) founding population about 40,000 years ago. If we assume that the European population was relatively genetically homogeneous during the mesolithic, then their average TMRCA is recent, then we get an influx of farmers from the near east during the neolithic, these new people are introducing genes for which the average TMRCA is at least 30,000 years before. That is, we get a new admixed mediteranian population, but it has a much older average TMRCA because it now contains European paleolithic genes (recent TMRCA) and Near Eastern neolithic genes (old TMRCA). Actually what probably happens is we get an admixed population all over Europe, but in the south we get a >50% Near Eastern component and in the north we get a <50% Near Eastern component. This may all be speculation, but this is a well know model for the observed genetic diversity in Europe. It is not inconsistent with a western Ice Age refuge source for the people of the British Isles.  # The papers using the SNP data are not designed to produce usable data here, they are not intended to suggest ancient population movements or relationships. the Dupanloup paper produces similar results and is more applicable to the article. The analysis of the 10,000 SNP data is arse-backwards, in order for it to produce meaningfull results for the sort of article we have here, the data need to be manipulated differently. Instead of looking for structure in populations, they should be looking for structure in the distribution of the SNPs. For example they should identify several sets of SNPs: ##The set of SNPs that occurs only in Europe. ##The set of SNPs that occurs only in northern Europe. ##The set of SNPs that occurs only in southern Europe. ##The set of SNPs that occurs in the Near East and in Europe. ::If the geographical distribution of these SNPs were plotted on a map, they might reveal something about migrations and relationships between peoples. I would bet good money (and I am not a betting man) that their results would be similar to Dupalon's. That is I suspect that they would find that the real difference between north and south Europe is the neolithic expansion. These data could then be used to model certain hypotheses. Unfortunately at the moment researchers seem to be more interested in finding genetic differences between so called ``populations`` (that is t