With emphasis on haplogroup H5 and H6.
Marta Mielnik-Sikorska et al., The History of Slavs Inferred from Complete Mitochondrial Genome Sequences. PLoS ONE 2013. Open access → LINK [doi:10.1371/journal.pone.0054360]
Most interesting is maybe table 1 (right), which lists two Polish populations (Kashubia, at the Baltic coast, and Podhale: the Carpathian piedmont), Ukrainians and Czechs.
We can see here that the most common lineages among these Slavs are not different from other European populations, namely H*, H1, U5a, U5b and also the, arguably Neolithic, lineages J1 and T2. I find relevant in this sense that there is a significant amount of T(xT1,T2) among Kashubian Polish especially.
Another point of interest is the minor presence of North and Central Asian lineages A, C, D and G, for which the authors present an elaborate rationale:
... we were able to pinpoint some lineages which could possibly reflect the relatively recent contacts of Slavs with nomadic Altaic peoples (C4a1a, G2a, D5a2a1a1).
They also suggest that the L2a1l2a, found among the Polish, is of Ashkenazi Jewish origin. L1b1a8 found in Polish and Russians belongs to the wider L1b1a, recently argued to be European-specific.
Another point of notice may be the rare HV0(xV) found at significant frequencies among Ukranians (4.5%).
But the authors make a particular effort to discern within haplogroups H5 and H6, which they find of particular interest. H5 might be (with doubts) of Italian origin and they consider its coalescence age (on the dubious molecular clock estimate methods) as clearly pre-Neolithic.
Based on these speculative methods they argue that several Slavic-specific clades within H5 may be contemporary in origin with U4a2, common in Central and Eastern Europe. They consider both to be roughly from Early Neolithic times.
If they are correct in their interpretation of the tempo of H5, the hypothesis of H sublineages migrating Northwards, from Southern to Central Europe, within Neolithic would seem to gain some support.
However H5 is less common in the Czech Republic and Austria than in Poland or Ukraine and the Neolithic colonization of Poland should have gone via the Czech Republic and, previously, Austria. Of course we cannot reject upfront a founder effect specific to Poland but what about Ukraine, which was almost totally oblivious to the Balcano-Danubian Neolithic phenomenon?
The other focus is H6, which is found almost only among Ukranian and Czechs of the four target populations. Generally speaking H6a and the most rare H6c are European, while H6b is Central and West Asian. In spite of its extreme rarity, the authors detected H6c in three individuals (one Czech, one Pole and one Slovak), all non-Slavic H6c are from Central-West or NW Europe (or from unknown locations). This seems to define H6c as a rare Northern-Central European haplogroup (excluding Eastern Europe apparently).
The remaining H6 samples sequenced in our study belong to different H6a subclusters being identified as singletons (H6a1a*) or as members of subclusters H6a1a4, H6a1a9 and H6a1b3. Subcluster H6a1a9 is novel, comprising of two haplotypes found in Russians and Ukrainians. Subcluster H6a1b3 is also interesting because it contains, except for European individuals of unknown origin, a founder haplotype of Czech origin and two Polish haplotypes.
|Figure 2. Complete mtDNA phylogenetic tree of haplogroup H6 (legend as above).|