Phylogeographic analysis of selected Alpine land snails

The widely accepted opinion about locations of Pleistocene refugia in Mediterranean and southeast Europe has been challenged by recent studies postulating more northerly or even Alpine refugia. The focus of our project is to establish a more detailed view on differentiation processes in the Alpine region, colonization routes, and finally on the evolution of species. In the centre of our interest are three selected Eastern Alpine land snail species: Cylindrus obtusus, Orcula dolium, and Trichia hispida. The latter two are rather widely distributed species, but several subspecies occur only in high altitudes of the Austrian Alps. The high alpine snail C. obtusus is a endemic of the Eastern Alps and represents a monotypic genus, morphologically highly distinct from related taxa. Taking these species as model organisms we want to analyse the genetic diversity of partially sympatric taxa endemic in the Eastern Alps which are restricted to high elevations. The data will be compared with those from related species/subspecies to evaluate patterns of intra- and interspecific diversification and to estimate the time frame for the population splits. We will investigate whether common patterns of intraspecific variation exist, which might be caused by the same historical events, e.g., advance and retreat of glaciations, climatic shifts or changes in vegetation. On the basis of the genetic data the phylogeographic history of these taxa will be deduced enabling us to establish scenarios about glacial refugia and (re)colonization routes. Both nuclear and mitochondrial markers will be employed in the genetic analyses. Concordant patterns obtained with different markers can be taken as a confirmation that the results reflect species history. Like many Alpine snail species, O. dolium, and T. hispida have been subdivided into several subspecies based on minor morphological differences and/or geographic and altitudinal distribution. Combining the genetic results with morphological and geographic data we will be able to address questions concerning gene flow, delimitation of the described species/subspecies as well as their taxonomic status. In addition, we will assess to which extent morphological characters (e.g., genital anatomy, shell morphology) are useful for systematics of the taxa investigated. For the morphological analysis digital image processing methods will be applied. One special case to be analysed in more detail are the genital organs of C. obtusus which proved to be highly variable in the eastern populations, while the more western populations were rather uniform. Therefore, a comprehensive morphometric investigation of the genital apparatus over the whole distribution range will be performed. Subsequently it will be assessed whether morphological and genetic diversity is correlated.

The widely accepted opinion about locations of Pleistocene refugia in Mediterranean and southeast Europe has been challenged by recent studies postulating more northerly or even Alpine refugia. The focus of our project is to establish a more detailed view on differentiation processes in the Alpine region, colonization routes, and finally on the evolution of species. In the centre of our interest are three selected Eastern Alpine land snail species: Cylindrus obtusus, Orcula dolium, and Trichia hispida. The latter two are rather widely distributed species, but several subspecies occur only in high altitudes of the Austrian Alps. The high alpine snail C. obtusus is a endemic of the Eastern Alps and represents a monotypic genus, morphologically highly distinct from related taxa. Taking these species as model organisms we want to analyse the genetic diversity of partially sympatric taxa endemic in the Eastern Alps which are restricted to high elevations. The data will be compared with those from related species/subspecies to evaluate patterns of intra- and interspecific diversification and to estimate the time frame for the population splits. We will investigate whether common patterns of intraspecific variation exist, which might be caused by the same historical events, e.g., advance and retreat of glaciations, climatic shifts or changes in vegetation. On the basis of the genetic data the phylogeographic history of these taxa will be deduced enabling us to establish scenarios about glacial refugia and (re)colonization routes. Both nuclear and mitochondrial markers will be employed in the genetic analyses. Concordant patterns obtained with different markers can be taken as a confirmation that the results reflect species history. Like many Alpine snail species, O. dolium, and T. hispida have been subdivided into several subspecies based on minor morphological differences and/or geographic and altitudinal distribution. Combining the genetic results with morphological and geographic data we will be able to address questions concerning gene flow, delimitation of the described species/subspecies as well as their taxonomic status. In addition, we will assess to which extent morphological characters (e.g., genital anatomy, shell morphology) are useful for systematics of the taxa investigated. For the morphological analysis digital image processing methods will be applied. One special case to be analysed in more detail are the genital organs of C. obtusus which proved to be highly variable in the eastern populations, while the more western populations were rather uniform. Therefore, a comprehensive morphometric investigation of the genital apparatus over the whole distribution range will be performed. Subsequently it will be assessed whether morphological and genetic diversity is correlated.