РусскийBrief annotation of the Sub-Program II
ORIGIN AND EVOLUTION OF LIFE ON EARTH:
PHYSICOCHEMICAL, GEOLOGICAL, PALEONTOLOGICAL, AND BIOLOGICAL PROBLEMS
HEADS OF THE PROGRAM:
Vice-president of RAS, President of SB RAS, Academician N.L.Dobretsov,
Head of the Department of the Institute of Microbiology of RAS, Academician G.A.Zavarzin
Formation of life on the Earth has passed through the period of the pre-biological evolution and evolving of the primary self-reproducing systems (SR-systems). The subsequent evolution of the SR-systems lead to the global expansion of life on Earth of a huge variety of forms on the land-based space, in the aquatic and air spaces, and the upper horizons of the lithosphere, that were formed as a result of co-evolution with the inert matter the biosphere of our planet, which corresponds to the highest level of life hierarchical organization on Earth. The biosphere corresponds to the hierarchically highest level of organization of life on the Earth. In the non-living nature, the matter has evolved from the inflationary state, which left to us the relict radiation, to the up-to-date state of the Universe, with its super-structure, galaxies, stars, and planets with the life existing on the only planet, the Earth. The studies of the last years has detected the role of determinism and stochasticity in the open systems with the same dynamic processes that have provided, in the end, the appearance of Earth and biological forms of life, together with principally important selection between these forms.
Notably, in the kingdom of minerals that has been appeared far prior the origin of life, there exist analogs of self-reproducing systems, that is, crystals and crystalloids, which although not being alive, but possess by ablity to self-reproduction. Crystal lattice serves as a memory, which like a matrix orders the structure of the subsequent layer of the growing crystal; in parallel, this lattice performs some functions of reparation. The analogue of this mutation is the fixed in the crystalloid structure alteration of the angle of the crystalloid lattice. However, the principal difference of the crystals from the biological SR-systems is the lack of compartmentalization and self-regulation of the crystal growth. The interest to the crystals expressed due to the problem of the origin of life is explained by the fact that their well-ordered regulatory systems could serve as a basis for the non-template abiogenic synthesis of biopolymers, thus, giving the start to the process of life evolution.
Obviously, the period of the life origin was preceded by the period of the pre-biological evolution, the first stage of this period is related to non-template abiogenic synthesis of basic organic substances, being the substrates for the origin of life.
Up to now, there exist three hypotheses, differing in principle, on the origin of initial organic compounds-substrates for the origin of life on Earth. According to the “primary broth” hypothesis, abiogenic synthesis of the major primary organic substances took place at certain sites on the Earth surface. According to the “panspermia” hypothesis, the life originated in the space and fell to Earth with an interstellar dust delivered here with meteorites. According to the hypothesis of “catalytic reactor”, abiogenic synthesis could commence in circumsolar disk, prior the planets were formed. Under definite conditions (temperature, pH, etc.), which are considered by each of hypotheses, the synthesis of a large spectrum of organic substances (amino acids, sugars and nitric bases, or, in other words, monomers of proteins, DNA and RNA was produced. The synthesis of analogues of the primitive biological macromolecules, i.e., short oligonucleotides, polypeptides, as well as proteinoids – branched proteins possessing by rudiments of enzymatic activity and ability to form the microspheres was made. A suggestion was worked out that the natural selection has been initiated at the chemical stage of evolution of a substance and that it is related to such chemical processes as, for example, the Butlerov’s reaction.
An important stage in understanding of the regularities in pre-biological evolution is related to the discovery of natural RNA molecules possessing by enzyme activity – rybozymes. Enzymatic activity of RNA enabled to revise the concept of early stages of the origin of life and formulate the widely known concept of the “RNA world” based on supposition that exactly RNA was the pre-biological self-replicating informational templates.
Known to us life on the Earth may be determined as the integrity of covariant reproducing genetic systems that function and self-reproduce on the basis of matrix principle of storage, transmission, and realization of genetic information. Biological information is the inherited alteration of properties and characters of the living organisms in a series of generations. In the course of biological evolution, the concordance between the properties of living organisms and conditions of the environment that they inhabit are being supported. Since conditions are being constantly changing, due to the vital activity of the organisms themselves, only the individuals that are better adapted to living in the alternated conditions of the environment were conserved, hence, the properties and characters of living creatures are constantly modified. Conditions of living on the Earth are infinitely varying, so adaptation of organisms to living in these differing conditions has generated in the course of evolution fantastic variability of living forms.
Thus, the variability of life in its ecosystemical, trophic, behavioral, morphological, physiological, cellular, biophysical, and molecular aspects, has ultimately the genetic nature and is the result of differential reproducing of genetically determined programs of organisms and their interaction with each other and with the surrounding environment.
From the very beginning of biological evolution, the divergence of the living organisms takes place. It brings with it exponential complication of the systems of cooperative and competitive interactions of remote genetic factors inside genomes and living organisms. Thus, novel and novel ecological niches appeared. Settling of novel ecological niches by some taxa, in its turn, was accompanied by complication in organization of living organisms. Progressive complication of organization took place towards different directions and at different rate in various taxonomic groups. Random duplications of genomes or their elements served as the material for complication. Due to this process, the genomes appeared that had necessary informational capacity for coding of information needed for supporting reproduction and functioning of complicatedly organized forms of living. Inherited alterations in the duplicated regions have been accumulated under the action of natural selection, thus, bringing the alteration in the ways of storage, transmission, and realization of genetic information and related to it separation of functions and specializations of cells and organs. Thus, the mechanisms supporting the reliability of reproduction of genetic information, are fine and plastic regulation of the phenotypical penetration of this information. In such a manner, the block-modular type of genome organization typical for eukaryotes has originated and was constantly improving. Random subsequent duplications and recombinations of these modules have provided pronounced acceleration in the rate of evolution and enlargement of biological variability in some taxa.
From the moment of origin of life on the Earth, the interaction between biotical and abiotical components was intensified, thus, causing active alteration and rearrangement of both biosphere and geosphere. The subsequent co-evolution of bio- and geospheres has initiated gradual evolution of variable biotopes on the Earth and corresponding to these biotopes forms of living. Essentially, the evolution of life took place against the background of geological rearrangements on the surface of Earth (plate tectonics, orogenic processes, glaciations, formation and destruction of continental bridges, etc.). Evidently, all these processes had a global impact on the evolution of life and its general direction, as well as channeled the evolution of particular life forms. From the other hand, living organisms have actively modified the geosphere.
Evidently, each of these co-evolving components (referring to bio- and geospheres) has its own specific internal mechanisms, factors, and driving forces. The evolution of life is based on evolution of genetic programs supporting reproduction, functioning of organisms and their interaction to each other at the populational, ecosystemical, and biospherical levels. Evolution of inert environment is determined by geological, geochemical, physico-chemical factors and processes. Interaction of two global vectors of evolution (biota and inert media of the planet) is one of the most important driving forces in evolution of the biosphere.
The most important for the humankind stage of progressive evolution is the process of antropogenesis, which had lead to origination of the modern man possessing consciousness, Homo sapiens. Studies of molecular-genetical and ecological prerequisites, mechanisms, and consequences of this process in the context of geological events that have preceded and accompanied it, are interesting not only from theoretical viewpoint, but also present huge practical interest.
By taking into account all the evidence mentioned above, we plan to provide the following directions of the research within the frames of the current project:
- Problem of abiogenic synthesis and chemical evolution of a substance during the period from pre-geological stages of formation of Earth till beginning of Archaean era.
- Problem of matrix-free synthesis of organic substances in biomineral systems.
- Problem of the “PNA World” (the simplest self-reproducing systems on the RNA-matrices).
- Problem of Archaean- Proterozoic biological systems.
- Problem of biogeoaromorphoses and co-evolution of abiotic and biotic events.
- Problem of genetic mechanisms of progressive biological evolution.
- Problem of molecular-genetic mechanisms of anthropogenesis.
By taking into account inter-disciplinary character of studies, it will be held within the frames of on-going Project, which will be executed by the institutions of the Russian Academy of Sciences and scientific teams from the universities of Russian Federation, as well as by the foreign scientific organizations working in the fields of Life Sciences, Earth Sciences, chemistry, mathematics and informatics, and the humanities. The organizations given below will participate in the Project:
Institute of Catalysis SB RAS, Joint Institute of Geology, Geophysics, and Mineralogy of SB RAS, Institute of Computational Mathematics and Mathematical Geophysics of SB RAS, Institute of Cytology and Genetics SB RAS, Institute of Systematization and Ecology of Animals of SB RAS, Institute of Biophysics of SB RAS, Limnlogical Institute of SB RAS, Institute of Automatics and Electrometry of SB RAS, Institute of Mathematics of SB RAS, Institute of Geology and Geophysics of Urals Department of RAS, Paleontology Institute of RAS, Moscow State University, Saint-Petersburg State University, Tomsk Pedagogic University, Omsk State University, Institute of Chemical Biology and Fundamental Medicine of SB RAS, Institute of Biology of Gene of RAS, Institute of Molecular Biology of RAS, Institute of Biological Chemistry of RAS, Institute of Molecular Genetics of RAS, Institute of Geology (Petrozavodsk), Institute of Microbiology of RAS, Siberian Research Institute of Geology, Geophysics and Minerals, Institute of General Genetics of RAS, Institute of Biology of Development of RAS, Institute of Biology of Gene, Tomsk State University, Zoological Institute of RAS, Botanical Institute of RAS, Institute of Biology of USC RAS, Institute of Ecology and Genetics of Microorganisms of RAS (Perm), Institute of Populational Genetics and Human Evolution by name of M. Plank (Germany), Institute of Anthropology of the Vienna University (Austria), Museum of Anthropology.