[The evolutionary role of predatory mammals and mechanisms of its realization].

Considered are the interactions within food chains that allow to refine the mechanisms of selective prey taking, which is important for better understanding of the evolutionary role of predation. By use of greyhounds, the hunting by wild canids is modelled for the purpose of repeated reproduction of searching for, chasing, and taking off the prey. It is found out that parameters of chasing (i.

[Crucial stages of embryogenesis of Rana arvalis: Part 3. Modularity or developmental integrity].

Static analysis of the morphometry of larvae of the postembryonic stages of development of Rana arvalis made it possible to estimate the extent and nature of correlations between developing structures. Considering a correlation as a manifestation of multiple physiological interactions between developing structures, we showed that the most likely scenario is the development of larval structures as a holistic process that is accompanied by an increase in the proportion of minor correlative interactions with an increase in the total number of structures. During the critical periods of development, an increase in the proportion of stronger correlative interactions between the structures that form at this stage of development is observed.

[Relation between fundamental and realized ecological niche].

Since species are formed in course of evolutionary process, their ecological niches are formed in the evolutionary process, too. Species exist in a state of evolutionary stasis diring hundreds of thousands and millions years. Stasis in sustained mainly by counterbalance of vectors of directional selection.

[Crucial stages of embryogenesis of Rana arvalis: Part 2. Development of head structures].

Analysis of the dynamics of variation in developing head structures of moor frog (R. arvalis) tadpoles has made it possible to reveal periods in which the limits of variation in relevant traits are narrowed. In the course of individual development, these so-called crucial periods for certain traits are followed by such periods for other traits.