PHENETIC MONITORING OF POPULATIONS OF THE NORTHERN RED-BACKED VOLE (CLETHRIONOMYS-RUTILUS PALL) IN THE ZONE OF THE EASTERN URAL RADIOACTIVETRACE

Monitoring of populations of the northern red-backed vole, carried out in the Kamenskii raion, Sverdlovskaya oblast, over two years (1992 an d 1993) revealed that increased morphological diversity accounted for by an increase in the number of small morphogenetic aberrations and ma lformations in the skull structure steadily manifested itself in the e xposed territory (along the axis of the Eastern Ural Radioactive Trace -EURT). It is revealed that the exposed sample has a steady undirectio nal deviation from the control ones, located outside the EURT zone, wi th respect to the frequencies of the phenes of nonmetric cranial trait s, which do not depend on annual conditions and testifies to the genet ic nature of the distinctions. It is assumed that these differences ar e accounted for by the chronic effects of small radiation doses on the processes of individual development in the northern red-backed vole a nd the accumulation of small genetic aberrations leading to the manife station of an increased concentration of phenotypic malformations in t he EURT zone.