My Polish wife is pretty, and pretty dark too. Jet black hair, dark skin, suffers in the Polish winter from a lack of sunshine (a vitamin D thing).
Here's some better info than what you gave...
Recent years have seen the publication of a plethora of genetic reports dealing with the Polish population. As a result we now have a fair idea about the Poles' genetic structure and position in Europe. In many ways these studies have challenged traditional anthropological and historical research on Poland, which often claimed the Poles to be strongly mixed with a variety of ethnic groups that have migrated to the region over the centuries.
In a nutshell, the Poles appear to be typical northern Europeans genetically. They generally cluster with the other Indo-European speakers of the region, and show differenecs from Finno-Ugrian and southern European populations. Foreign influences on the Polish genetic pool, both from different parts of Europe, as well as from outside of Europe, appear to have been minor.
Let's first take a look at the sex biased genetic data...
In terms of Y-chromosome haplogroups the Poles are quite "Slavic". In other words, they are similar in this respect to the their ethnic kin in the east, the Russians and Ukranians. The most common haplogroup in all three nations is R1a - the dominant haplorgoup in eastern Europe. However, the Russians and Ukranians generally carry more of haplogroup N, which is seen most often in Finnic and Altaic populations. This suggests that the eastern Slavs absorbed Finno-Ugrian elements as they expanded east from their region of ethnogenesis.
Western European influence on the Poles via Y-chromosome haplogroups has not been great. Haplogroup R1b, most often seen in Celtic and Germanic populations, is found at levels of 7-17% in Poland. The typically Germanic I1a is even rarer, occuring at less than 6% in Poland as a whole.
In appears that the German, Dutch, Scottish, French and Italian migrants of the middle ages left a much lesser mark on Poland's population than previously thought. Invasions of Poland by Germans and Swedes also appear to have been rather minor influences on the present Poles' paternal makeup.
And it seems that migrants and invasions from the east have been even less successful in this respect. Typically East Asian and Siberian haplogroups, such as C and Q respectively, are extremely rare in Poland. The Finno-Ugric N, which is thought to have an East Asian origin, and was probably also carried by invading Asian nomads, is commonly found at 3-4% in Poland. However, most of this haplorgoup in Poland is probably due to Lithuanian admixture, and not direct Asian influence. N is found in about 40% of the population in Lithuania, which was joined with Poland for centuries as part of the Polish-Lithuanian Kingdom.
Typically Near Eastern haplogroups such as J and G are also uncommon in Poland. Western and southern European populations, as well as the Ukranians and southwest Russians, carry more of these Middle Eastern markers than Poles. This argues against any significant Jewish, Armenian and Turkish influence on the present Polish population, despite these groups' well documented presence in Polish history.
More detailed haplotype Y-chromosome data support the findings of the broader haplogroup surveys, but also throw up a couple of surprises. Poles show some similarities to Germans, but more so to Russians. They also tend to share haplotypes with Lithuanians and Latvians, which might be a sign of the common Balto-Slavic origin of these groups. Yet in the end, the Poles also show a remarkable homogenity and distinctiveness.
Population samples from Germany and Russia also showed similarities to Polish populations, with relatively small RST-values on pairwise comparisons (0.0176-0.097). It is noteworthy that all but one of the comparisons between the six Polish populations and the Russians revealed statistically non-significant differences (0.05 0.001).
From "Homogeneity and distinctiveness of Polish paternal lineages revealed by Y chromosome microsatellite haplotype analysis".
Haplotype data is also more useful than haplogroups when focusing more closely on the paternal admixture from Asia. For example, although R1a is common in Poland, it's also common among Tatars. So in this instance it would be difficult to tell whether or not the Tatars contributed to the Polish gene pool. However, according to the YHRD database, haplotypes typically seen in Turko-Mongol groups of Central Asia are rare in Poland, even if they represent typically European haplogroups such as R1a and R1b. They make up less than 1% of the combined Polish sample.
Moving onto the other 50% of sex biased DNA, the maternal mtDNA...
Differences in mtDNA within Europe are not major. In northern Europe populations speaking Slavic, Germanic and Baltic carry the same basic haplogroups in very similar frequencies. Poles do show some similarities to Russians in this respect that would suggest a common Slavic origin. However, they also share rare mtDNA markers with Germanic speakers.
Mitochondrial DNA (mtDNA) control region sequences were determined in Poles (n = 436) and Russians (n = 201). Despite the high mtDNA diversity, both populations are characterized by similar pattern of mtDNA haplogroup distribution, which is also typical for many European populations studied.
From "Mitochondrial DNA analysis in Poles and Russians"
Our results indicate that AvaII morph and haplogorup composition of the Polish population is similar to oher European populations and has a distribution typical for this part of the world. However, statistically significant differenes in haplogroup composition were found between the Polish population and Italian and Finnish populations.
From "Comparison between the Polish population and European populations on the basis of mitochondrial morphs and haplogroups".
At the same time, Poles carry about 1.8% of the East Asian haplogroup M. It's somewhat of a mystery how this foreign maternal admixture found its way into the Polish gene pool, considering that the Turko-Mongol invaders of the middle ages were largely male.
Since the Baltic populations to the north carry less than 1% of these Asian haplogroups, and European Russians about 1.5%, it is more likely that they found their way to Poland from the south. Czechs are known to carry 3% of East Asian mtDNA, probably as a result of admixture from the Huns, Avars and Magyars. Therefore, the most likely scenario is that women with Turko-Mongol admixture moved to Poland from such regions as Moravia, Slovakia and Hungary, rather than directly from Asia.
Sub-Saharan African specififc mtDNA haplogroups are much more unusual in Poland, and appear more commonly in such western European countries as Germany and France.
And now onto Autosomal (non-sex biased) tests...recognised as the best way to test population structure.
More recent studies looking at thousands of genome wide Autosomal markers have firmly put the Poles in the same cluster with northern Europan populations such as the Irish, English, Germans and Swedes. This perhaps suggests that these populations share ancient links which are not apparent when comparing the fast mutating Y-chromosome markers discussed above.
Please note that in the first digram Poles are shown along with other Eastern Europeans in pink (EEURA). In the second. they are shown seperately in green. In both diagrams they cluster strongly with the "Northern" samples.
From "European Population Substructure: Clustering of Northern and Southern Populations"
Interesting to note...
Regardless of the European country of origin, each of those participants with four grandparents of Ashkenazi Jewish heritage showed this predominant "southern" cluster membership.
This could be more proof that Poles and Jews rarely mixed during their many years of co-existance.
Another Autosomal study came up with similar conclusions...