Phylogeography of a Darevskia (caucasica) complex (Lacertidae: Sauria) based on the cytochrome b mitochondrial gene analysis

The range of superspecific complex of rock lizards Darevskia (caucasica) (D. alpina, D. c. caucasica, D. c. vedenica, D. daghestanica) includes the Main Caucasian ridge and its spurs on the southern and northern macroslopes within heights from 500 m to 3200 m above sea level. A fragment of the mitochondrial cytochrome b gene (1096 bp) was analyzed in 48 specimens of these lizards. Specimens were collected in 23 localities. We have found 39 unique haplotypes. The minimum genetic diversity was found in D. c. vedenica, maximum in D. c. caucasica. All taxa of the complex, except for D. c. vedenica, demonstrate genetic heterogeneity. Four clades can be distinguished on the dendrogram of phylogenetic relationships. They correspond to D. alpina, D. c. caucasica, D. c. vedenica, D. daghestanica. D. c. caucasica forms two distinct haplogroups. On the phylogenetic tree, the sample of D. c. vedenica formed an independent clade close to D. c. caucasica. The Darevskia (caucasica) complex is polyphyletic according to the analysis of the mitochondrial marker. Nucleotide sequences of D. alpina formed a single clade with Darevskia (saxicola) complex representatives and combined with the sequences of D. brauneri into subclade. On the example of the population of D. daghestanica, found in a forest biotope without rocky outcrops and genetically not differing from individuals from the adjacent territory, the ability of rocky lizards to master biotopes unusual for them in a short period of time was demonstrated. This example demonstrates the ability of rock lizards to adapt to unusual biotopes in a short period of time. Genetic distance between D. c. vedenica and D. c. caucasica is comparable to the distance between D. c. caucasica and D. daghestanica. We assume the existence of an independent form of D. caucasica ssp. inhabiting South Ossetia and adjacent territories.