Investigation of variability structure of root vole (Microtus oeconomus Pallas) molar morphotypes using bilateral asymmetry [Russian]

摘要

Specimens (720) of the root vole Microtus oeconomus Pallas were sampled (1982-1995) in the Mountain Altai and analyzed for bilateral morphotypic variation in M-1 and M-3 molars. There is a direct asymmetry in both molars: more complicated morphotypes develop significantly more often on the right side. No correlation between M-1 and M-3 asymmetry indices was found (r = 0.0012; n = 714). This fact indicates that the bilateral asymmetry of molars develops independently in the course of ontogenesis. The Cavalli-Sforza's distance was calculated between frequency of the morphotypes. The principal components method was applied for processing of the data. The morphogenetic similarity of the morphotypes obtained by this way coincided with the visual one. Factually, the morphogenetic similarity system of M-1 is two-dimensional, that of M-3 is three-dimensional. The results obtained confirm that variation of discrete phenes is of continual nature with threshold display.