Multiple glacial refuges of unwinged ground beetles in Europe: Molecular data support classical phylogeographic models

Abstract

Since the 1930s, several European zoologists have developed scenarios for glacial refuges and postglacial expansions, mainly based on studies of the morphological differentiation of populations and distribution patterns of species. For example, Holdhaus described the distribution of blind euedaphic and troglobitic beetles restricted to an area South of a well-defined line crossing the Southern Europe from West to East. In these areas, where many endemic animal and plant species occur, other species that are currently more widely distributed in Europe were probably able to survive the glacial period(s). Molecular analyses of 77 populations of the silvicolous ground beetle Carabus auronitens support the existence of these postulated refuge areas. Genetic differentiation of C. auronitens provides good evidence for multiple refuges, which are, however, situated further North than previously assumed. Furthermore, genetic differentiation is more pronounced in the areas South of the Holdhaus line than in the areas North of it.