Intraspecific allozymatic differentiation reveals the glacial refugia and the postglacial expansions of European Erebia medusa (Lepidoptera: Nymphalidae)

Allozyme analysis of Erebia medusa over large regions of Europe revealed a significant population differentiation (F_ST: 0.149 ± 0.016). A UPGMA-analysis showed a division into four major lineages with mean inter-group genetic distances ranging from 0.051 (±0.010) to 0.117 (±0.024). An AMOVA revealed that rather more than two-thirds of the variance between samples was being between these lineages and less than one-third within lineages. An eastern group included the samples from the Czech Republic, Slovakia and north-eastern Hungary. This genetic lineage expressed significantly higher genetic diversity than the other three. A second lineage was formed by the samples from France and Germany. The two samples from western Hungary represent a third delimited lineage and the sample from northern Italy a fourth. We suppose that this genetic differentiation took place during the last ice-age in four disjunct refugia. The genetically more diverse eastern genetic lineage might have evolved in a relatively large refugium in south-eastern Europe. We assume that the other three lineages developed in relatively small relict areas around the Alps. It is likely for the western lineage that its ice-age distribution showed at least one disjunction in late Würm with the consequence of further genetic differentiation. Most probably, the eastern lineage colonized postglacial Central Europe using two alternative routes: one north and one south of the Carpathians. Up to now, neither similar glacial refugia, nor comparable secondary disjunctions in late Würm, are reported for any other animal or plant species.