Zhurnal obshchei biologii最新文献

In this paper we present a review of individual differences in animal behavior exemplified by fishes. Main approaches to these differences investigation are outlined. Such terms as temperament can be used to describe consistent characteristics of individuality in animals. It should be emphasized that consistency over time and across situations is the main classification characteristic of the temperament trait. We also briefly review genetic and physiological mechanisms of individuality in fish, factors affecting their development in the ontogeny, and effects of the individual experience. Significant adaptive value of temperament is shown: in many cases the natural selection maintains alternative behavioral tactics. We also consider the main quantitative models accounting for the coexistence of individuals with different behavioral patterns. Finally, it is demonstrated that patterns of behavioral individuality may significantly affect population dynamics.

Soil emission of carbon dioxide, the key component of carbon cycle and the characteristic of soil biological activity, has been studied in background and polluted ecosystems in the Kola subarctic, the large industrial region of Russia. Long-term air pollution by emissions of "Pechenganikel" smelter, the largest source of sulphur dioxide and heavy metals in Northern Europe, has caused the technogenic digression of forest ecosystems. As a result of the digression, the tree layer was destructed, the number of plant species was diminished, the activity of soil biota was weakened, the soils were polluted and exhausted, biogeochemical cycles of elements were disturbed and productivity of ecosystems shrunk. Field investigations revealed the decrease of the in.situ soil respiration in average from 190-230 mg C-CO2/m2 x per h in background pine forests to 130-160, 100, and 20 mg C-CO2/m2.per h at the stages of pine defoliation, sparse pine forest and technogenic barrens of the technogenic succession, respectively. The soil respira- tion in birch forests was more intense than in pine forests and tended to decrease from about 290 mg C-CO2/m2 x per h in background forests to 210-220 and 170-190 mg C-CO2/m2 x per h in defoliating forests and technogenic sparse forests, respectively. Due to high spatial variability of soil respiration in both pine and birch forests significant differences from the background level were found only in technogenic sparse forests and barrens. Soil respiration represents total production of carbon dioxide by plant roots and soil microorganisms. The decrease in share of root respiration in the total soil respiration with the rise of pollution from 38-57% in background forests up to zero in technogenic barrens has been revealed for the first time for this region. This indicates that plants seem to be more sensitive to pollution as compared to relatively resistant microorganisms. Soil respiration and the contribution of roots to the total respiration positively correlated with distance from the smelter and the content of carbon and nitrogen and negatively correlated with the content of available nickel and copper in the soils. Remediation of technogenic barrens promoted intensification of soil biological activity. At the same time, the willow planting along with grass seeding into the new constructed fertile soil layer was much more effective for activation of soil respiration and the contribution of roots to the total respiration than the planting into the limed and fertilized polluted soils (chemo-phytostabilization).

After discussion of many years about the nature of plants community, within the science dealing with vegetation the consensus is reached on pragmatic basis. Most researchers consider plants community as conditionally uniform contour marked out of the multi-dimensional continuum of any type of vegetation. Plants community is a generic notion, within the framework of which types with different models of organization are established. With any type of plants community organization model, the main factor of species association remains to be the ecotope which plays the role of an abiotic matrix. The main traits of a plants community are species composition, its structure, species interrelations, and functional parameters. The main types of species interrelations within a plants community appear to be competition and non-competitive formation of environment. The important role in organization of plant communities belongs to heterotrophic organisms such as phytophages, nitrogen-fixing procaryotes, mycorrhizal fungi, pathogens, and others.

Subspecies is the only taxonomical category inferior to species which application is governed by the International Code of Zoological Nomenclature. Although the first attempts to use it are dated by the end of XVIII century, it becomes regularly applied only by the middle of XIX century, along with trinomial nomenclature. At that, the current sense of the term, i.e. subspecies as a morphologically and spatially separated population group or as a synonym for "geographical race", has become established even later, by the end of XIX century. The concept of polytypic species, which has already taken shape in 1900s (in the works by ornithologist E. Hartert and entomologist K. Jordan), has been incorporated later into the modern evolutionary synthesis. The peak of the concept popularity fell on 1940-50s, then the evident crisis of subspecies systematics began to show, and is still showing nowadays, especially in systematics of invertebrates. The reasons behind the drop of subspecies category popularity are discussed, among them the emergence of novel species concepts where the rank of subspecies is not used (the phylogenetic species concept), impossibility to verify the validity of previously described subspecies by means of statistics or molecular systematics, etc. Nevertheless, in systematics of vertebrates, the category of subspecies still remains called-for.

Eriophyoids is a group of highly specialized plant-feeding acariform mites. As a result of adaptation to phytoparasitism, they lacked III and IV pairs of legs and acquired elongated vermiform body and unique structure of gnathosoma. Despite the high degree of specialization, eriophyoid mites demonstrate remarkable evolutionary plasticity which manifests itself in numerous morphological reversions, parallelisms, and modifications associated with occupying variety of niches, processes of gall formation, transitions to new groups of hosts, and various adaptations to climate change.

The molecular biology success, which became influential for a revision of principal views on the relationships and evolutionary pathways of major groups ("phyla") of multicellular animals, were much more appreciated by palaeontologists rather than by neontologists. This is not surprising because this is the fossil record that serves as a firm test for molecular biological hypotheses. The fossil record indicates that the different "phyla" united nowadays into the Ecdysozoa, namely, arthropods, onychophorans, tardigrades, priapulids, nematomorphs, comprise a number of transitional forms having become extinct already in the early Palaeozoic. The very appearance of those organisms fits entirely to hypothetical ancestral forms which have to exist in accordance with some data on ontogeny. There are no even tentative intermediates between arthropods and annelids in the fossil record. The oldest Deuterostomia, which is the only branch of the Bilateria being agreed upon by all the biological disciplines, allow us, although in less details, to present their early history and point to agile bilaterally-symmetrical forms at the dawn of chordates, hemichordates, and echinoderms. The interpretation of the early history of the Lophotrochozoa is even more difficult because in comparison to other bilaterians, their oldest fossils are preserved as mineralized skeletons only. However, a unity of microstructures of molluscs, brachiopods, and bryozoans, absent in other metazoans, is indicative of the presence of close relatives among different earliest lophotrochozoans some of which are sedentary filterers while others are motile epibenthic detritophages. In the aggregate, modern data of molecular biology, palaeontology, and comparative embryology/morphology, having got a second wind with an introduction of new microscopy techniques, imply that the suggestion of a planktotrophic gastraea-like common ancestor is the least possible among diverse suggestions on the Metazoa origins. The common ancestor of the Bilateria had to be a motile epibenthic animal and the explosive metazoan diversification embracing the late Ediacaran--early Cambrian interval (c. 40 Ma) was probably a real event, which was predated by a long (c. a billion years) assembly of the metazoan genome within unicellular and colonial common ancestors of the Opisthokonta and even the Unikonta as a whole.

The research of hemocytes of laboratory cultivated pond snails Lymnaea stagnalis originating from two areas near Chernobyl with different radiation load has been carried out by means of comet assay. Significant interpopulation distinctions in parameters of DNA-comets have been revealed by means of the software analysis of hemocyte DNA-comet images: hemocytes of mollusks from radiationally unfavourable "Perstok" population have contained a twice DNA quantity in comparison with "Pripyat" population, and also have been statistically more resistant to the influence of strontium. Strontium reduces the amount of DNA in hemocytes, at that strontium dose of 0.5 MPC is already substantial (i.e., causes a negative impact).for snail Lymnaea stagnalis. According to a RAPD-analysis previously conducted, the snails of two populations are characterized by high genetic similarity, on the basis of which a hypothesis is suggested that the observed differences in the DNA content of hemocytes and resistance to strontium are inherited as prolonged adaptive modification (epigenetic change) in response to the intensive damaging impact of environment. Comet assay can be its indicator while carrying out the environmental monitoring.

Discussed are the possibilities of using syntaxa from floristic classification for the analysis of secondary restorative successions after forest cutting in South Ural Region. Peculiarities of secondary forest communities classification that may be viewed as subjects of indigenous vegetation syntaxa forming, sub-associations or could be systematized according to 'deductive' classification introduced by K. Kopecky and S. Heiny are considered. An example is presented of an analysis of communities succession system formed after cutting down hemiboreal pine and birch-pine herbaceous forests of Bupleuro-Pinetum association. Within this system the processes of divergence and convergence of succession series take place. Divergence occur as a result of lifting of the influence caused by dominants edificating role and manifestation of differences in soil humidification, also as a consequence of soil enrichment by mineral elements after burning down the felling debris. The reason behind convergence is grading influence of renewed forest stand. Trends in species richness changes during restorative successions may differ depending on ecotope features. In course of a succession, models of tolerance and inhibition become apparent.

Plastids are photosynthetic DNA-containing organelles of plants and algae. In the review, the history of their origination and evolution within different taxa is considered. All of the plastids appear to be descendants of cyanobacteria that colonized eukaryotic cells. The first plastids arose through symbiosis of cyanobacteria with algal ancestors from Archaeplastida kingdom. Later, there occurred repeated secondary symbioses of other eukariotes with photosynthetic protists: in this way plastids emerged in organisms of other taxa. Co-evolution of cyanobacteria and ancestral algae led to extensive transformation of both: reduction of endosymbiont, mass transfer of cyanobacteria genes into karyogenome, formation of complex system of proteins transportation to plastids and their functioning regulation.

The expediency of a modular approach to estimating fluctuating asymmetry (FA) of complex morphological structures was shown using the mandible of the bank vole (Clethrionomys glareolus Schreber, 1780) as an example. FA of the shape of two mandibular regions (modules) defined developmentally and functionally, was assessed by means of geometric morphometrics. The differences between mandibular regions in the FA levels were found for both individual landmarks and integral indices of asymmetry. Regardless of age, gender or sampling year, FA estimates obtained for posterior region including part of the ramus and processes were higher than those for anterior region including the diastemal area. The results suggest that modularity of complex morphological structures should be taken into account when analyzing FA.