Phylogeography and morphological variation in a narrowly distributed Caucasian rock lizard, Darevskia mixta

The Caucasian rock lizard Darevskia mixta was sampled and studied from throughout its range, using mitochondrial cytochrome b sequences and scalation. The populations of the Greater and the Lesser Caucasus are reciprocally monophyletic matrilineally, and the respective lineages have been separated since the mid-Pleistocene. The lizards from the Greater Caucasus commonly have an unpaired preanal scale, whereas the lizards from the Lesser Caucasus have an additional scale behind the central temporal and subdivided interparietal scale more commonly than those from the Greater Caucasus. The Lesser Caucasus populations are further subdivided into two geographically distinct matrilineages, and are more diverse genetically and morphologically than the Greater Caucasus populations. The central part of the Lesser Caucasus is suggested to be the ancestral area for the entire D. mixta lineage. Successive Pleistocene periods of glaciation appear to be responsible both for the isolation of D. mixta from its common relatives, and for subdivision within D. mixta. Presence of D. mixta in NE Turkey is challenged.