|Laboratories \ Laboratory for Microevolution and Domestication of Mammals \ Goals and Tasks|
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LABORATORY FOR MICROEVOLUTION AND DOMESTICATION OF MAMMALS
MAIN GOALS AND TASKS
The head of Laboratory
Ecology of organisms and communities
The peculiarities of feeding for herbivorous mammals and their food supply as a basis of energetic and material balance of animals were determined. The role of forage quantity and its quality (nutritive value) in the provision of full-value nutrition was estimated. The food value of different types of fodder vegetation was characterized which was dependent on composition of nutrients (fats, proteins, carbohydrates etc.) and effectiveness of their intestinal uptake (gastrointestinal digestion).
The relation between population state, number and distribution of several species (little ground squirrel, siagas, wild sheep) and feeding quality (digestible ability, nutrients content etc.) of graze vegetation was established, the critical parameters of the quality of natural graze vegetation for animals satisfaction of needs in energy and protein were determined. The peculiarities of fodder vegetation put on the limitations on diversity, distribution and number of herbivorous mammal populations.
The reaction of populations, their number and distribution to the change of feeding quality of vegetation was estimated. It was shown that even at exuberance of food and its maximal consumption the animal needs in nutrients and energy were not satisfied, if the forage quality (digestible ability, protein content etc.) was below the critical level. The threshold levels for the quality of fodder vegetation were determined, below which the populations were not able to function sustainable.
The studies in the steppe and semi-desert ecosystems showed that for provision of full-value feeding and availability of mammalian population, a regulated graze exploitation of the ecosystems was necessary. Cessation or abatement of depasturage lowered feeding value of vegetation and was accompanied by decrease in number and species diversity of animal population in graze ecosystems.
For the purpose of study and inventory taking of biodiversity, the taxonomic analysis was undertaken for complex polytypic species and superspecies complexes of mammals of Palearctics, Eastern Africa and South Asia with the use of molecular-genetic methods, analysis of the generative structure system, morphometry etc.
It was shown that big polytypic species and superspecies complexes of rodents and insectivorous mammals represented complex systems of taxa, forming 4-6 levels of hierarchy, and not two (the species and subspecies) according to the Codex of Zoological Nomenclature. For adequate characteristics of biological diversity in any concrete case it is necessary to describe maximally the hierarchic system of the taxa, really existing in nature, in accepted trinomial nomenclature, which taxonomists are impelled to use.
It was shown that real biological diversity of mammals is greatly higher than that which was possible to reveal, using morphological taxonomical features. A range of genetically unique intraspecies taxa was revealed and is under study. A conclusion was made that any similar taxon, independently from the degree of its reproductive isolation and morphological differences, had to have a scientific name and, if necessary, to be conserve like any biological species.
Systematics of modern rodents (the orders Rodentia, Mammalia) of the Palearctic fauna was developed (more than 30 species) o the basis of molecular-genetic data. For the first time, molecular-genetic diagnosis for the species was composed, which included the peculiarities of the chromosomal structure, protein molecules, DNA and RNA. On this basis, a phylogenetic classification of the species was created and species independence of several forms was substantiated.
Differentially stained chromosomes of a common shrew
For the first time the proofs of the role of glacier isolates and alternate of divergent (in isolates) and reticular processes in acceleration of intraspecific formation. A method, allowing revelation of the correlation between phenotypic and genotypic variability in morphological features was developed. In the developed method genetic variation of the character was characterized by "equilibrium parts of genotypes" and "conditioned alleles", which were calculated according to equation of Hardy-Wainberg.
The principle of allele differentiation into ancient and evolutionary young ones in dependence of their distribution throughout the range of big polytypic species and in different allospecies was developed.
On the basis of analysis of geographic variation in caryotype, protein genes and molecular peculiarities of big polytypic species of mammals, a new model of geographic speciation has been elaborated, in accordance to which the species origin in the process of multiple alternate of the periods of entire great species areal, when chromosomal and gene mutations spread throughout the species range and genetic variability of populations increases ("zonal phase") and periods, when the whole areal or only a part of it disintegrates into isolated populations ("refugial phase"). This evolutionary process was named as refugial formation and speciation.
With the use of the data on sequence analysis of a short retroposon (SINE) B1, reconstruction of phylogenetic relations of the families of the order of Rodentia was carried out for the first time. Monophyly of three basic evolutionary lines was revealed. According to the data analysis of mobile genetic elements, the family of beavers appeared earlier than miodontic rodents. For the first time, a good coincidence of reconstructions of phylogeny was demonstrated that evidenced a high reliability of molecular-genetic reconstructions of phylogeny.
With the use of the methods of biochemical genetics, it was shown that adaptive possibilities of the species were not bound with the level of general gene variability. Ecological specialization of the species-siblings can be followed both by accumulation and loss of protein polymorphism. The possibilities of adaptation of the species are determined by a minor part of the total gene variability or by monomorphic part of genome.
By the methods of computer modeling it was shown that in the working process on breeding in captivity of Przevalsky's horse and European wisent, the loss of 50% of genetic material of animal-founders took place. With the use of computer technologies, the parameters of genetic diversity, necessary for long-termed existence of these species populations were calculated.
Introduced populations of wisent (demographic and genetic analysis, structure and perspectives of development) were studied in the forest and steppe-forest zones, including National Park "Orlovskoe Polesye" and Ust'-Kubenskoe Forestry in Vologda Region.
The key parameters of territory selection for creation of wisent populations were determined and a plan-scheme for territory survey with the purpose of adaptability for wisent population creation was developed. The steppe territories in Orenburg Region, suitable for re-acclimatization of Przevalsky's horse, were surveyed and selected.
By the methods of biochemical genetics, reintroduced and native populations of European wisent were studied. It was shown that successful expansion and adaptation to forage resources in the range of the previous habitat of this valuable fur-bearing species were connected with a quick formation of genetic subdivision of populations and maintenance of the high genetic variability of the species.