Allozyme polymorphisms in the small heath, Coenonympha pamphilus:: recent ecological selection or old biogeographical signal?

Allozyme electrophoresis is a common tool to analyse the genetic structure of populations with a focus on conservation and biogeography. An essential requirement for biogeographical analyses is the independence of the applied methods from ecological,selection processes. We surveyed the genetic population structure of Coenonympha pamphilus as a model species to validate allozym electrophoresis as a method for such studies. We analysed 106 individuals of C. pamphilus of the Monte Baldo region (southern Alps, Italy) at different altitudes and 82 individuals from two populations north of the Alps (Germany). The F-ST among all populations was 9.7% but no significant differentiation was observed along the altitudinal gradient in the Monte Baldo region. Our results revealed no influence of the climate on the allozyme frequencies, thus excluding a major importance of recent selection processes for the observed differentiations. These results support the suitability of allozyme electrophoresis for biogeographical studies.