Non-concordant phylogeographical patterns of three widely codistributed endemic Western Balkans lacertid lizards (Reptilia, Lacertidae) shaped by specific habitat requirements and different responses to Pleistocene climatic oscillations

摘要

The Balkan Peninsula is a hot spot for European herpetofaunal biodiversity and endemism. The rock climbing lizards Dalmatolacerta oxycephala and Dinarolacerta mosorensis and the ground-dwelling Dalmatian wall lizard Podarcis melisellensis are endemic to the Western Balkans, and their ranges largely overlap. Here, we present a comparative phylogeographical study of these three species in the area of their codistribution in order to determine the level of concordance in their evolutionary patterns. Phylogenetic analyses were performed based on two mitochondrial genes (cytochrome b and 16S rRNA), and a molecular clock approach was used to date the most important events in their evolutionary histories. We also tested for correlations regarding genetic differentiation among populations and their geographical distances. For all three species, a significant correlation between genetic and geographical distances was found. Within D.oxycephala, two deeply separated clades ('island' and 'mainland clade'), with further subdivision of the 'mainland clade' into two subclades ('south-eastern' and 'north-western'), were found. High sequence divergences were observed between these groups. From our data, the time of separation of the two main clades of D.oxycephala can be estimated at about 5mya and at about 0.8mya for the two subclades of the mainland clade. Within D.mosorensis, coalescence time may be dated at about 1mya, while D.mosorensis and D.montenegrina separated around 5mya. The results imply the existence of complex palaeo-biogeographical and geological factors that probably influenced the observed phylogeographical patterns in these lacertid species, and point to the presence of numerous glacial/interglacial refugia. Furthermore, the observed cryptic genetic diversity within the presently monotypic species D.oxycephala prompts for a revision of its taxonomic and conservation status.