[An analysis of isometric reflections in morphology exemplified by the mandible of the rat (Rattus, Rodentia)].

Individual, age, sex, and species differences of morphological shape is treated as a result of general shape formation process. It is assumed that mutual reflections of these differences could be described by continuous and discontinuous transformations. The first type of these reflects equilibrium properties of shape formation, while the second type reflects its non-equilibrium properties. Equilibrium process is strongly canalized and is able to generate quite limited diversity of shapes. Contrary to this, non-equilibrium process can generate a lot of different shapes, as it destroys canalized relations between characters. Idea of equilibrium process provides a background for formulation of null hypothesis about anticipated relations between characters. Statistically significant deviations from these relations allow to recognize characters that mark areas of possibly non-equilibrium transformations. Analysis of localizations of all such characters allows to formulate more meaningful hypothesis about shape transformations for a particular morphological object. Some easily available statistical methods of recognizing characters that reflect either continuous of discontinuous transformations are exposed using mandible of three rat species as an example. It is shown that discontinuous transformations are located mainly in the same areas of mandible in all modes of inter-reflections. Characters (linear measurements between morphometric landmarks) with continuous inter-reflections describe transformations of general shape of the mandible. Characters with discontinuous inter-reflections mark boundaries between functional blocks and areas with the heaviest dynamic loads.