Differentiation of population of the northern red-backed vole Clethrionomys (=Myodes) rutilus from the North-East Siberia according to analysis of morphotypical variability of masticatory surface pattern of the third upper molar (М3)

Abstract

In different populations of the northern red-backed vole (Clethrionomys rutilus) of the North-East Siberia polymorphism of the masticatory surface structure of the third upper molar (М³) was studied. According to М³ morphotype frequency distribution, the northern red-backed vole populations in the considered region are divided into two groups.
The first one occupies the Kolyma River basin and the north-western coast of the Sea of Okhotsk, the second one – the basins of the Anadyr and Paren’ Rivers and Kamchatka Peninsula. Such population differentiation of C. rutilus is in good agreement with data on molecular genetic studies of the species. Scheme of formation of two phyletic lines of the northern red-backed vole in North-East Siberia in late Pleistocene is suggested.