[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.e., speed, distance, duration) are important for hunting but not determinative. There can be a high actual selectivity determined by prey conditions and, at the same time, low success of chasing. The mechanisms of recognition of potential prey availability or unavailability are analyzed. The data are presented that indicate that superficial microflora can be considered as a common marker of various, deviations in the state of a prey. Unlike stabilizing selection, which preserves separate traits, selection by predation stabilizes the phenotype as a whole.

[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. Niche can be viewed as a multidimensional structure. Multitude of environmental factors acts upon every population, which cause elimination and, by that, selection for adaptation to each eliminating factor. Different directions of these vectors of selection lead to their counteractions; selection in one direction is interfered by selection in an opposite direction. The counterbalance of vectors of selection interferes with progressive evolution thus supporting stasis. During species existence in a stasis condition it endures a whole set of various deterioration of environment. Such deteriorations lead to imbalance of selective processes. Unbalanced vectors of selection form adaptations to extreme conditions of existence. Such adaptations are superfluous as for usual conditions; but they define fitness borders and, by that, borders of a fundamental niche. Realized niche, as well as fundamental one, is a multidimensional structure. Each population occupies a subniche of the specific realized niche. Thus, it occupies habitats where conditions are as close to an ecological optimum as can be admitted by the conditions in the given part of the areal. The sum of all subniches of populations--the specific realized niche--coincides with a part of fundamental niche because only the part of adaptive possibilities of a species sufficient for existence in the given environment is used. Interspecific competition, even when it is capable to restrict consumption of limiting resources, is not the reason of the realized niche limitation. Restriction of one or two of niche parameters does not influece all others parameters of its multidimensional space.

[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. However, crucial stages for some head structures have not been revealed, which can be explained by a relatively short period of development considered in the study. Analysis of individual variation at later stages may provide the possibility to identify crucial periods for these structures.

[Factors influencing the hunting success of a predator: a model with sighthounds].

Using microbiological criteria (the number of CFU in nose prints on agar medium), it has been shown that the proportion of individuals with a high CFU count is significantly higher among brown hares caught by sighthounds or exposed to immobilization stress than among shot hares. A hypothesis is proposed that metabolites of the body surface microflora in animals exposed to long-term stress account for their specific stress odor. Observations on wild hare coursing with the use of GPS tracking (1-s update rate) provide evidence that hunting success is not directly dependent on the absolute and relative coursing speeds, the number of sighthounds, and the distance, duration, and number of coursingevents. An analysis has been performed of stress odor as a universal criterion allowing the predator to estimate the vulnerability of potential prey. Selective elimination of unhealthy (stressed) individuals by predators is a mechanism of natural selection for increased adaptation of populations and species to the effects of a broad spectrum of environmental factors.

[Crucial stages of embryogenesis of R. arvalis: Part 1. Linear measurements of embryonic structures].

Investigations of individual variability have allowed us to reveal the crucial (= nodal) stages in embryogenesis of the moor frog (Rana arvalis Nills.). These crucial stages are: the late gastrula stage (stages 18-20), the hatching stages (stages 32-33) and, apparently, early metamorphosis (stage 39). Moreover, we have found that each embryonic structure passes through its specific crucial stages. For example, stage 34 is crucial for the trait "tail width" but is internodal for all other embryonic traits. At this stage, larva passes from an attached to a free-swimming life style. We also found considerable differences between the different frog populations in the the level of developmental variability. These differences were associated with internodal developmental stages.

[Causes and conditions of formation of the aromorphic organization].

Analysis of data concerning the origin of terrestrial vertebrates allows to conclude that the organism undergone the aromorphosis (=arogenesis) not only improves the general degree of organization, but also becomes able to survive in much more complex and diversified environment than its ancestors and, consequently, expands the ancestor's adaptive zone. It was shown that aromorphosis occurs when the ancestral taxon specializes in a narrow adaptive zone having vacant neighboring zone which might be occupied. The aromorphic adaptations are formed very slowly in the course of so-called coherent evolution by accumulation of certain multiply adaptations and by their coordination with each other. In the end, the set of these adaptations overrides the oscillation range of environmental conditions in the ancestral adaptive zone and can be considered as a pre-adaptation to adaptive zone expansion. Some features which are characteristic for the modem 'aromorphic' groups such as Tetrapoda, Avia and Mammalia, appeared independently and asynchronously in many related taxa. However, appearance of a few detached features does not help to widen an ancestral adaptive zone. Taxon becomes really aromorphic only due to the simultaneous formation of all adaptations allowing the expansion of ancestral adaptive zone, i.e. successful exploration and occupation of neighborning adaptive zone.

[Mechanisms of adaptive regulation of early development of Anuran amphibians dwelling the anthropogenically polluted water bodies].

Comparison of the gastrulation in three Anuran species has shown the possibility of evolution of earlier morphogenesis directed to adaption to such new environmental factor as anthropogenic pollution of water bodies. Changing proportion of variability and correlation of the developing embryonic structures causes changes in the character of morphogenetic processes to the point of discoordinated development and formation of heterochronies and/or increased death rate. In the studied amphibian species, the increase of the concordent development in different populations resulted either from increased general correlation of morphogenesis or from the emergence of a group of traits with more interdependent development. Mechanisms of early development regulation comply with a single scheme, which indicates the nonspecificity of early embryogenesis reaction based on epigenetic regulation mechanisms.

[Interpopulation comparison of variations in gastrulation of Rana arvalis and Rana ridibunda occurring under the conditions of anthropogenic contamination of water bodies].

The results of morphometric analysis of gastrulation in city populations of Rana arvalis and Rana ridibunda suggest that under the conditions of anthropogenic contamination of water bodies, the early development is more variable, if we compare less variable sizes of their eggs in the city and suburb populations. The variability of gastrulation appears to depend on the degree of contamination of spawning water bodies and is accompanied by increased correlation between the forming structures. This latter may be determined by two causes: (1) increased number of interdependent features, which leads to coordinated differentiation of structures and regulation of variability, and (2) increased coefficients of correlation within a small group of features, which leads to the formation of structures characteristic for the subsequent developmental stages, including the appearance of heterochronies.

[Comparison of variability of Rana temporaria (Amphibia, Anura) gastrula from different populations developing under the conditions of antropogenic pollution].

The gastrulation of Rana temporaria embryos was studied at the natural spawning sites of Moscow city and Moscow district by means of morphometric analysis. We demonstrated that anthropogenic pollution plays an important role in morphogenesis of Anura. The measurements of embryos from the Moscow ponds made it possible to show an increased variability of gastrulation. Moreover, the level of gastrulation variability depends on the degree of pollution of a spawning pond and is coupled with increased correlations between the morphological features. This increase of correlations could be due to: (1) an increased number of correlating features (appearance of new correlations) and (2) strengthening of the existing correlations. The first way makes the gastrulation process more coordinated, and the second one causes the appearance of morphological structures, which are normally formed only at the next developmental stages.

[The correlation of the ecological niches of the common (Rana temporaria L.) and of the moor (Rana arvalis Nilss.) frogs (Anura, Amphibia)]. / Sootnoshenie ékologicheskikh nish travianoi (Rana temporaria L.) i ostromordoi (Rana arvalis Nilss.) liagushek (Anura, Amphibia).

During 25 years ecology and population dynamic of two brown frog species (Rana temporaria and R. arvalis) were studied in Moscow region, Solovki island and South Ural. We compared life cycles characteristics, namely biotope preferences, diet, migration, enemies, hibernation places using own and available literature data. Then we analyse how these parameters are changed among the species area and ecological niches were compared. We found that these two species do not compete in any stage of life cycle. Ecological niches are very closed and differences are determined generally by abiotic factors. So, R. temporaria prefers more wet biotope and more sensitive to acidity (low pH value). Differences in spawning time do not associate with interference in spawning places. We conclude that interspecific competition did not take place neither in the past nor in present and the reason of differences in ecological niches are determined by separate ways of evolutionary development of these species.

[Dynamics of numerical changes in human population in terms of animal population ecology]. / Dinamika chislennosti chelovechestva s pozitsii populyatsionnoi ekologii zhivotnykh.

The author uses data concerning the natural regulation of population size and growth among animals to consider possible future scenarios for human population growth. Four possible variants are considered: "numerical stabilization and its consequences connected with density effect; sharp slump caused by a global ecological catastrophe; limited slump brought about by exhaustion of resources and environmental pollution; numerical decrease through birth regulation. It has been shown that only the last variant can, in [the] case of the human population being 1.2-1.5 billion people, ensure restoration of [the] biosphere with keeping [the] existing tempo of scientific-technological progress." (SUMMARY IN ENG)

Mechanism for the origin and the evolutionary significance of heterochronia.

Using material on the evolution of the fundus of the oral cavity in amphibians, four principles were established for the origin of heterochronia: efficiency of ontogenesis; adaptability of an earlier (than in ancestors) beginning for functioning of traits; loss of the adaptive significance of a trait at a previous stage, but a preservation of it at a subsequent stage; and, a prolongation of the adaptive significance of a trait at later stages. The origin of heterochronia is associated with changes in the succession of the functioning of genes, with reorganization of systems of morphogenetic correlations, and with change in the traits themselves that undergo heterochronia. The uniqueness of heterochronia as an adaptation consists of an increase in the evolutionary flexibility of specific stages of ontogenesis.