Phylogenetic analysis of the Lacerta agilis subspecies complex

The Sand lizard Lacerta agilis inhabits a huge area across Eurasia with several subspecies. Nine subspecies are generally approved, L. a. agilis, L. a. argus, L. a. bosnica; L. a. chersonensis, L. a. exigua, L. a. grusinica, L. a. iorinensis, L. a. brevicaudata and L. a. boemica, but several more have been described. The emergence of this large number of subspecies is connected with the phylogeographic history of this species, defined by geographic and climatic processes. A study revealing phylogenetic relationships of this species was already conducted with a broad taxon sampling and coverage. However, the latter study was based solely on the cytochrome b gene and, furthermore, the Balkan Peninsula inhabited by the subspecies L. a. bosnica was underrepresented. This peninsula is a centre of European herpetofaunal endemism with high levels of phenotypic and genotypic variation. Therefore, the inclusion of the subspecies L. a. bosnica is important to clarify the overall view of the phylogenetic relations within the Lacerta agilis subspecies complex and to investigate the level of population differentiation within this highly diverse area. Thus, the aim of the present study was a more thorough analysis of the Balkan Peninsula with a broader taxon sampling. Furthermore, we extended the available datasets by adding the mitochondrial d-loop region and by further samples of different areas of the distribution range apart from the Balkan Peninsula. Our study reveals that the Balkan Peninsula is apparently inhabited by several differentiated lineages, whereby the Central Greek lineage might deserve subspecies status. Furthermore, the distribution area of the two subspecies L. a. agilis and L. a. argus should be revised, as the results of our study raise doubt about the commonly assumed distribution of both subspecies. As the most important outcome our results support that L. a. boemica deserves species status.