Genetic and Morphological Variability of the Ural Field Mouse (Apodemus (Sylvaemus) uralensis, Rodentia) in the North Caucasus.

The genetic and morphological variability of the southern form of the European chromosomal variety of the Ural field mouse Apodemus (Sylvaemus) uralensis (Pallas, 1811) in the North Caucasus was studied. The results of the sequence analysis of the cytochrome b gene fragment from nine geographical samples from the western, central, and eastern parts of the North Caucasus indicate a low degree of their genetic isolation with a relatively high diversity of haplotypes. Analysis of the morphological variability revealed high variety: three morphological groups were identified. Representatives of all three or two groups were found in the same geographical samples, but their distribution did not conform to the hypothesis of random occurrence. Based on indirect evidence, hypotheses about possible causes of the observed features of regional Ural field mouse biodiversity are formulated, which require verification in the course of future studies. In particular, we hypothesized that in the Late Pleistocene (130 000–11 700 cal years BP) there were several isolated populations in the region that could have been sources of species diversity in the Holocene. [ABSTRACT FROM AUTHOR]