Mitochondrial DNA variation in Eisenia n. nordenskioldi (Lumbricidae) in Europe and Southern Urals.

There are many peregrine European earthworm species that are found in Siberia. In contrast, it is generally considered that the only Siberian species, E. n. nordenskioldi, was capable to disperse in the reverse direction, from Siberia into Europe. We studied genetic diversity of E. n. nordenskioldi in Southern Urals and Eastern Europe using the mitochondrial cox1 gene. We found that E. n. nordenskioldi from that region represents a new genetic lineage distinct from the previously known populations of this species from Siberia. Molecular clock estimates suggest that this newly found lineage separated from the rest of the species in Lower Pleistocene. Within the studied sample, we detected two geographically restricted groups, which also diverged long before the Holocene, one found in the East European Plain and the other restricted to the Urals. Those two groups were found in sympatry in only one population. Therefore, our results do not support the traditional viewpoint, suggesting that E. n. nordenskioldi is definitely not a recent invader in Europe.