Surviving at sky islands? - Recent study questions ancient theories about the relict status of alpine grasshoppers in Europe (Acrididae, Gomphocerinae, Podismopsis)

Sky islands give a good opportunity for evolutionary studies, because selection and genetic drift can be particularly strong in island systems. The five European species of Podismopsis are known from the European Alps (Switzerland: P. keisti, Austria: P. styriaca), from Montenegro (P. relicta), in the Carpathians (P. transsylvanica), and from northern Russia (P. poppiusi). All species are endemic to small montane and alpine areas at altitudes over 1800 m a.s.l. It is supposed that the cold adapted (boreoalpine) Podismopsis-species survived glaciations in the cold Asian steppes of Siberia (P. poppiusi) or in lower altitudes in Europe (all other species). The time of disjunction and whether the interglacial fragmented populations came into contact during latitudinal shifts during glacial periods is still unclear, but multiple climatic-induced vicariance events during Pleistocene could be suspected.

Because of the low species number, the immobility of all species, and the strong adaptation to alpine habitats we expect Podismopsis to be old relict species and therefore we study the differentiation processes through bioacoustical and molecular methods.

Until now we analysed P. keisti, P. styriaca and P. relicta. Our preliminary results show small phenotypic and genotypic divergence between these species. Therefore, it seems that at least these three species might be quite closely related despite their relict occurrence and expected ancient fragmentation.