[An analysis of form variability by the methods of "geometrical morphometry": the demonstration of its potentials exemplified by the gnathosoma of ticks (Acari: Ixodes) and by the molar of voles (Mammalia: Alticola)].

New applied computer programs GRF, TPSRW, TPSLINE realize an idea of geometrical morphometrics and make it possible to study shape variation. Some results of their application are considered. Gnathosoma shape transformations among age and sex phases in tick, Ixodes ricinus, and third upper molar shape transformations among subspecies of vole, Alticola argentatus, are study cases. In tick, gnathosoma shape changes most significantly in males than in females, and age variation in total has twice higher magnitude as compared with sex differences. In vole, the most variable part of the tooth is talon, in general its complexity increases from south to north of the species area. A possibility of "vector" representation of principally "scalar" individual variation of the tooth shape is shown.