Evolutionary divergence of the smooth snake (Serpentes, Colubridae): The role of the Balkans and Anatolia

Abstract

The smooth snake Coronella austriaca (Laurenti, 1768) is distributed across the western Palearctic throughout north-central, southern Europe and western Asia. So far, only few phylogenetic studies, based on mitochondrial DNA, have been carried out on this species focusing mainly on the Iberian Peninsula and northern Europe, leaving unstudied some of important areas of its distribution. This study aims to cover this gap and to explore the phylogenetic relationships between the populations of in the Eastern Mediterranean and to detect possible historical refugia. With this objective, total genomic DNA was extracted from samples originated from the Balkans, Anatolia and a large part of Europe. Two mitochondrial (cyt b, 16S) and six nuclear (BDNF, NKTR, RAG1, RAG2, MC1R and PRLR) markers were combined for phylogenetic and chronophylogenetic analyses. The different analyses confirmed previous phylogeographic hypothesis showing the presence of several well-supported clades distributed in Anatolia, Central Europe, Eastern Europe, Western Europe, the Balkans and the Iberian Peninsula and cryptic diversity within Anatolia and the Balkans. Moreover, dating analysis confirmed the diversification of the species during the Pleistocene, as well as the role of the Southern Balkans and Anatolia region as refugia during this period.