Boreskov Institute of Catalysis of the Siberian Branch of Russian Academy of Sciences
EMERGENT LIFE DRINKS ORDERLINESS FROM THE ENVIRONMENT
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- PROTOBIOLOGICAL STRUCTURES, PREBIOLOGICAL AND BIOMINERAL COEVOLUTION Yushkin N.P.
- ORAL PRESENTATIONS OP‐1 ROLE OF COMETS IN THE ORIGIN OF LIFE AND ITS EVOLUTION
- OP‐2 GRAVITATIONAL INSTABILITY IN THE PROTO‐PLANET DISK Brushlinskii K.V., Pliner L.A., Zabrodina E.A., Menshov I.S.
- OP‐3 34 HOT ABIOGENESIS AND EARLY BIOSPHERIC EVOLUTION Helen Piontkivska 1 , Charles H. Lineweaver 2
EMERGENT LIFE DRINKS ORDERLINESS FROM THE ENVIRONMENT Russell M.J. Jet Propulsion Laboratory, MS: 183‐601, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, USA Microbes both at the bottom of the evolutionary tree and the base of the food chain hydrogenate carbon dioxide. Four billion years ago our water‐world could do the same (as it does still)—abiotically generating methane like an inorganic methanogen, though not nearly so quickly. More rapid reduction appears to be life’s raison d’être. So how did life begin? We can think of life’s emergence as being, in part, enabled by a series of self‐organizing “negative” entropy traps with serpentinization the first “demon”, transferring energy from the mafic crust to open‐system convecting ocean water in the form of heat, hydrogen, methane, ammonia as well as hydroxyl and sulfide ions (Martin et al., 2008, Nature Rev Microbiol, 6, 806). The initial trap would be set across the inorganic membrane, formed spontaneously at the site of exhalation of the reduced alkaline fluid now differentiated and separated from its mother liquor—the acidulous, phosphate‐ and ferrous iron‐bearing carbonic ocean (Nitschke and Russell, 2010, J. Cosmol, 10, 3200; Simoncini et al. J. Cosmol, 10, 3325). Inorganic transition metal sulfides could act as precursor catalysts to hydrogenase, nitric oxide reductase, carbon monoxide dehydrogenase and acetyl coenzyme‐ A synthase, while phosphate could be polymerized to pyrophosphate by protons streaming through the spontaneously precipitated inorganic membrane, in turn condensing and polymerizing the first organic products of hydrogenation and amination. Resulting highly flexible uncoded and heterochiral peptides could locally also lower entropy by sequestering inorganic sulfide and phosphate clusters, thereby improving and tuning their catalytic and energy‐storage propensities. Thus, such a system would already be capable of evolution through the survival of those peptides that nested or otherwise interacted with the inorganic entities within the compartments (Milner‐White and Russell, 2010, J. Cosmol, 10, 3217; Kurland, 2010, Bioessays 32, 866). Products not taking part in further interactions would tend to be entrained in the slowly diffusing effluent and be lost to the system. In further conceptual steps Dieter Braun and collaborators (e.g., Baaske et al., 2007 PNAS, 104, 9346) have demonstrated how convectively‐driven polymerase chain reactions whereby 24 25 DNA molecules that are replicated, albeit with the involvement of taq polymerase, are concentrated against entropy in “cold traps” within inorganic compartments through thermal diffusion driven by thermal gradients acting across the margins of a hydrothermal mound. We know entropy traps are also required for the onset of the RNA world. For example, Sievers et al. (2004, PNAS, 101, 7897) show that the peptide bonding rapidly effected in the ribosome is mainly a result of juxtaposing the substrates—perhaps aided by an unfolded peptide—to the partial exclusion water (and see Hsiao et al., 2009, Nucl Acids Res, 37, 3134; Wallin and Åqvist, 2010, PNAS, 107, 1888). [1]. Copyright 2011, California Institute of Technology. Government sponsorship acknowledged. PROTOBIOLOGICAL STRUCTURES, PREBIOLOGICAL AND BIOMINERAL COEVOLUTION Yushkin N.P. Institute of Geology of Ural Branch of Russian Academy of Sciences, 54, Pervomaiskaya st., Syktyvkar, 167982, Russia Fax: +7 (8212) 425346, yushkin@geo.komisc.ru Abiogenic highly structured solid carboniferous substances and hydrocarbon molecular crystals, rather widely developed in terrestrial and extraterrestrial objects, possess structural and functional elements of protocell, protogene, contain building components of protoprotein and represent the most appropriate prebiological systems for creation of information genetic apparatus and for development to the simplest living organisms. They can be considered as models of protobiological systems. We have conducted detailed researches of composition, molecular and supramolecular structure of various natural carboniferous substances and hydrocarbons, their comparative analysis with biological materials and biomineral aggregates. Abiogenic hydrocarbon structures, the most homological to bioorganisms, are crystallized to relatively high thermal and high baric conditions in hydro‐gaseous mineralized environment with carbonate‐chloride‐sulphate magnesium‐potassium‐sodium composition in the presence of ammonia, sulphur gas, methane, carbon dioxide and other components, in reducing conditions. Biological life could be originated under similar conditions. The formation of biomolecules and other components of life began yet at astrophysical stage. The first acts of biogeniesis apparently developed not on the Earth surface, but in hydrothermal systems, pegmatites, volcanos, possibly even in gaseous cavities of hardening melts. These events occurred in the beginning of crustal stage (4.5‐4 Ga) characterized by melting of basalts and their granulite metamorphism. Not casual events, but certain geoecological and physical‐chemical conditions resulted in the life origin. Life formed from prebiological material as single integrated whole, not as separate parts, casually united, or successive events. The simplest biological systems were hemoautotrophic. Prebiosphere was characterized by subsurface localization. The life was matured after protoorganisms were brought out to surface reservoirs, having changed to photoheterotrophic way, in warm water puddles and 26 27 in ocean. The primary biosphere had local insular character, then archipelago, and complete biosphere cover was acquired by the Earth at about 3.8‐3.7 Ga. Thus, the biosphere history includes: a) period of subsurface prebiosphere characterized by nearly exploding origin and enaction of the simplest life, b) period of formation of surface and near‐surface biosphere, c) stagnation procaryota‐eucaryota period, about 1.7 Ga, d) period of exponential biosphere expansion from 2.3 Ga to present. On the basis of quantitative, structural and event‐driven analysis of development of mineral and biological systems the mechanisms and regularities of biomineral coevolution were studied. During prebiological history of the planet the number of minerals increased from a dozen of nanosize phases in prestellar molecular matter to fifty in the primary preplanetary chondrite matter and to 250 – in primary planetary (crustal) one. This mineral substrate resulted in the sources of life origin and development. Mineral formation processes of non‐ biological nature supported mineral diversity in about 1500 mineral species, about 100 of them were generated by granitoid magmatism, granitization of granulites and related hydrothermal processes. A powerful biogenic factor was included into the evolution of mineral world together with life appearance on the Earth, which considerably renewed and complicated the evolution process. This factor became one of the leading in the formation of mineral pattern of near‐surface lithosphere, and as a consequence the number of mineral species increased at 3 times to 4500 known today. Oxidation processes are playing a great role in it. The biomineral evolution is characterized by precisely directed “loosening” of mineral matter expressed via decreasing total density of atomic array in minerals (PA) from 0.50 in preplanetary chondrite material to 0.44 – in basalt minerals, 0.40 – crustal, 0.38 – in modern mineral world. The total symmetry index decreased the same way: 33.58 29.00 21.95. Thus, biomineral interactions and their coevolution resulted in cardinal changes of mineral world of lithosphere expressed in sharply increasing mineral diversity, complicating structure, decreasing structural density and total symmetry, accelerating rate of biomineral genetic events. They promoted formation of modern appearance of lithosphere and biosphere, creation of modern biological and mineral diversity. OP‐1 ROLE OF COMETS IN THE ORIGIN OF LIFE AND ITS EVOLUTION Adushkin V.V., Pechernikova G.V. and Vityazev A.V. Institute for Dynamics of Geospheres, Russian Academy of Sciences, Moscow, Russia E‐mail: avit@idg.chph.ras.ru I. A current standard scenario of the origin of the Solar System is presented [1, 2]. The results of research of the earliest evolution stages of circumsolar protoplanetary disk with the Sun before its exit on the main sequence Hertzsprung–Russell diagram is considered. We examined the evolution of ensembles of gas‐dust clusters and planetesimals both in astrodynamical aspect and in terms of interiors thermal history of surviving in the collisions of bodies. The calculations take into account new data on the injection of 60 Fe into the young Solar system and the new value of a half life (2.62 million years instead of 1.5) of this nuclide. Calculations (ours and other authors) have shown that radionuclides 26 Al and 60 Fe have provided heating and differentiation of the interiors of planetesimals early in the first 3‐4 million years after formation of CAI. In the terrestrial planet zone early melting bodies with sizes ranging from tens to a few thousand kilometers makes it possible to explain the formation of differentiated bodies in the first 3‐4 million years of the Solar system existence and data on early differentiation of the planet's interior. In the zone of outer planets long before the formation of the planets themselves into planetesimals with sizes ranging from tens to hundreds of kilometres, formed from the gas‐dust clusters, the ice melting, the differentiation into the shells and cores descended from dust and its aggregates with organic matter occured. For astrobiologists, this result points to the need of searching for traces of anaerobic forms of life in the ice bodies of the Solar system or their fragments – comet nuclei. For geophysicists, our results on the heating of bodies of lunar size by short‐lived isotopes remove the old problem of early heating of the central regions of the growing planets. II. The role of comets is important not only in the formation of Earth, but also throughout its evolution. In a recent survey [3] it was noted, that neither hypothesis is not suitable to explain the mass extinctions of biota and the Glacials (duration about 30‐100 million years) on the Earth. Since 1960, several well‐known geologists (W. Brian Harland, Joseph Kirshvink – author of the term "Snowball Earth", Paul F. Hoffman and others) have 29 OP‐1 30 developed a theory of the great glaciations. But the very causes of the fall in average temperatures by at least 2‐5 °C were not clear. Many authors attribute some of globally recurring events with the motion of the Solar system in the Galaxy. During this movement, the Solar system have repeatedly met with the giant molecular clouds, periodically crossed the galactic plane, passed through the branches of the spiral structure, i.e. passed through the area of increased density of matter in the galaxy. During such periods, frequency of close encounters of stars with Solar system increased. This caused disturbance of comet orbits of the outer and inner parts of the Oort cloud, which, in turn, could lead to comet showers. Hundreds of comets were transferred to higher eccentric orbits and penetrated into the central regions of the Solar system, some of them collided with the Earth. But the comet's collision with Earth couldn`t lead to global catastrophe, it`s a local scale event. Vityazev A.V. [4] proposed a new mechanism of the Galaxy action on events on the Earth. During periods of comet showers stream of comets, moving in the direction of the Sun, crosses the asteroid belt. Cross section of collision of comets with numerous asteroids is on orders greater than their cross section of collision with the Earth. Calculations showed that the collision of a comet with an asteroid even much smaller in size but with higher density at an average velocity of comets in the asteroid belt about 30‐40 km/sec leads to complete destruction of comet and ejection of dust into interplanetary space. Estimations have shown that during the periods of cometary showers of a dust can be formed enough that reduction of an insolation of the Earth has led to approach of the next glacial age. References [1]. Adushkin V.V., Vityazev A.V., Pechernikova G.V. In the development of the theory of the origin and early evolution of the Earth // Problems of the origin and evolution of the biosphere / Ed. E.M. Galimov. Moscow: Librokom, 2008. P. 275‐296 (in Russian). [2]. Vityazev A.V., Pechernikova G.V. Early Earth in close environment of young stars // Problems of origin of life. Russian Academy of Sciences. Moscow: PIN RAS, 2009. P. 131‐157 (in Russian). [3]. Coryn A.L. Bailer‐Jones The evidence for and against astronomical impacts on climate change and mass extinctions: A review. //International Journal of Astrobiology, 8, 213‐239. [4]. Vityazev A.V. Could be caused Great glacial ages by comet showers? // Doklady Earth Sciences, 2011 (in press). OP‐2 GRAVITATIONAL INSTABILITY IN THE PROTO‐PLANET DISK Brushlinskii K.V., Pliner L.A., Zabrodina E.A., Menshov I.S., Zhukov V.T., Dolgoleva G.V., Legkostupov M.S. Keldysh Institute for Applied Mathematics, Russian Academy of Sciences, Moscow, Russia In spite of numerous studies, the main question of how the planetary system of the Sun has been formed remains still open. Large‐scale gravitational instability of the proto‐planet solar disk might be a physical process that leads to the formation of planets. However in the scientific society there is no common opinion concerning this question. Some researches consider the proto‐planet disk in the gas phase to be stable [1, 2]. Other researchers keep the opposite point of view [3, 4]. Thus, Pavlyuchenko and Friedman have found [4] existence of the gravitational ring‐shaped instabilities in the proto‐planet solar disk, which can lead under specific conditions to the formation of the solar planetary system. In calculations, they used a flat disk model with sufficiently small thickness. The purpose of the present paper is to study large‐scale gravitational instabilities at the initial stage of the proto‐planet solar disk evolution. The problem of the proto‐planet disk evolution in the general formulation is extremely difficult. In order to simplify this problem and make the treatment of the results obtained possibly unambiguous, several assumptions are employed. The medium of the disk is considered to be single‐phase and ideal. Of all physical processes, which occur in the proto‐planet disk, we leave only basic ones that influence the gravitational stability of the disk: gas‐dynamic processes, the Sun gravitational field, and the disk own gravitational field. The initial state of the proto‐planet solar disk is set up in accordance with the analytical solution by Roche [5, 6]. In this formulation, the proto‐planet disk has the form of a slim torus, whose internal part becomes narrow, if we go towards to the center. Strong gravitational field of the Sun draws the gaseous medium of the proto‐planet disk to the center, and due to this effect the density of the gaseous medium reaches maximum values near the internal edge of the disk. This creates significant density gradients. The problem of the proto‐planet solar disk evolution is solved numerically. A numerical two‐dimensional axisymmetric gasdynamic model, which accounts both the gravitational 31 OP‐2 field of the Sun and the field of the disk has been developed. This model describes the basic processes at the initial stage of the evolution. The description of gasdynamic processes is carried out in the Eulerian coordinates. The governing equations represent the basic conservation laws. These equations are discretized with the numerical method proposed by S. K. Godunov and A. V. Zabrodin [7] for solving gasdynamic equations in complex geometries on arbitrary moving grids. The whole computational domain is divided into a set of subdomains separated by moving boundaries. This approach allows us to sufficiently resolve different scales of the proto‐planet disk dynamics. The computational grid consists of 124800 cells in total. The developed numerical model simulates the initial stage of the disk evolution in the Roche’s approximation, when the disc inner field is neglected, and also with taking it into account. The comparison of these two calculations provides data on how the disk inner gravitational field influences on the process of the proto‐planet disk evolution. The analysis of the computational results shows that switching on the disk inner field changes the flow structure. Ring‐shaped domains begin to form, in which the flow so develops that it results in the mass concentration in certain radial cross‐sections of the disc. This can be clear seen from snapshots of instantaneous streamlines. When the inner gravitational field is switched on one can see the formation of several subdomains. The gas in each of these subdomains tends to move to a radial cross‐section, with the density being increased near this section. In comparison with the flow without the inner field, the flow in subdomains above the cross‐section lines oppositely changes the direction of motion. The contour lines of density in the proto‐planet disk are changed in accordance with the change in behavior of the streamlines. In Figs. 1 and 2 density contours are shown at two different time moments. As can be seen, the inner gravitational field causes the flow instability that develops in the form of the rings of density (Fig. 2). Local maximums and typical cross‐clamping of contour lines are well‐defined in the density distribution of the proto‐planet disk at the moment t=0.685 (non‐dimensional). The structure of rings is physically intelligible: appearance of the Jeans instability (i.e., local increase in gas density) leads to local mass concentrations that begin to gravitationally attract surrounding masses of gas, in consequence of which local maximum and cross‐clamping in contour lines come out. This corresponds to local decrease in the thickness of the proto‐planet disk. 32 OP‐2 33 Typical sizes of gravitational instabilities are equal in order of magnitude to the distances between the planets. The masses of the rings of the local maximums of density comprise fractions of the masses of the corresponding planets. Fig. 1. Density iso‐contours at time=0.299. Fig. 2. Density iso‐contours at time=0.685. References [1]. V.S. Safronov. Accumulation of the planets. In: Origin of the solar system (Ed. G. Rivs), Publ.: Mir, Moscow, 1976. [2]. A. V. Vityazev, G.V. Pechernikova, V.S. Safronov. Earth‐type planets: Origin and the early evolution. Publ.: Mir, Moscow, 1990. [3]. Ebert R., Habilitationschrift, Un. f. Frankfurt‐am‐Main, 1964. [4]. V.L. Polyachenko, A.M. Fridman. J. of Astronomy. V.49, No 1, p.157, 1972. [5]. A.V. Zabrodin, E.A. Zabrodina, M.S. Legkostupov, L.A. Pliner, K.V. Manukovskii. Some models of the description of proto‐planet solar disk at the initial stage of its evolution. Preprint KIAM RAS, No 70, 2006. [6]. A.V. Zabrodin, E.A. Zabrodina, M.S. Legkostupov, L.A. Pliner, K.V. Manukovskii. Some models of the description of proto‐planet solar disk at the initial stage of its evolution. In: Problems of origin and evolution of the biosphere (Ed. E.M. Galimov), Publ.: Librokom, Moscow, 2008, p. 297. [7]. S.K. Godunov , A.V. Zabrodin, and et al. Numerical solution of multidimensional problems of gas dynamics. Publ: Nauka, Moscow, 1976. OP‐3 34 HOT ABIOGENESIS AND EARLY BIOSPHERIC EVOLUTION Helen Piontkivska 1 , Charles H. Lineweaver 2 and David W. Schwartzman 3 1 Department of Biological Sciences, Kent State University, USA 2 Planetary Science Institute, Australian National University, Australia 3 Department of Biology, Howard University, USA, dschwartzman @gmail.com We argue that hyperthermophilic abiogenesis leading to a hyperthermophilic Last Universal Common Ancestor (LUCA) of life is supported by a wide range of recent research. If the ambient ocean during abiogenesis was cold, then primitive mesophiles should have emerged. The absence of deeply‐rooted mesophiles in molecular phylogenetic trees suggests that either primitive mesophiles did not survive a near sterilizing event in the Hadean or a hot Archean climate, or alternatively did not emerge because of a hot Hadean climate. Drawing on a plausible scenario of hydrothermal abiogenesis near the seafloor ((Russell and Hall 1997; Koonin and Martin 2005; Russell 2007), we propose that a spectrum of Bacterial and Archaeal protocells, including ancestors of extant prokaryotes, emerged simultaneously in the redox potentials of a thermal gradient between a hydrothermal source on the seafloor and the ambient climatic oceanic temperature in Hadean time. The transition from RNA to DNA and the efficient repair of single and double strand breaks in DNA, rather than being the result of a mesophile to hyperthermophile transition could be a consequence of the protocell emergence in a high temperature and high radiation environment due to intracellular K 40 and C 14 . Therefore the early accumulation of neutral ‘‘clock‐like’’ substitutions could plausibly be driven by this radiation dose as a function of time, with the surviving record having the potential of providing the time of emergence of the earliest metabolisms. The strong anti‐correlation of maximum growth temperatures (Tmax) of thermophiles with their rRNA and tRNA phylogenetic distances from the LCA supports their Tmax being close to the environmental temperature of each organism at emergence. A climatic temperature close to 70‐ 80 deg C in the late Hadean/Archean is consistent with paleotemperatures derived from oxygen isotopes in marine cherts ((Knauth, 2005), and the measurement of melting temperatures of proteins resurrected from sequences inferred from robust molecular phylogenies (Gaucher et al., 2008). [1]. Gaucher, E.A., Govindarajan S. and O.K. Ganesh, 2008, Palaeotemperature trend for Precambrian life inferred from resurrected proteins. Nature 451: 704‐707. [2]. Knauth LP. 2005. Temperature and salinity history of the Precambrian ocean: implications for the course of microbial evolution. Palaeogeogr. Palaeoclimatol. Palaeoecol. 219:53–69. [3]. Koonin EV, Martin W. 2005. On the origin of genomes and cells within inorganic compartments. TRENDS in Genetics Vol.21 No.12, 647‐654. [4]. Russell MJ, Hall AJ. 1997. The emergence of life from iron monosulphide bubbles at a submarine hydrothermal redox and pH front. Jour. Geol Soc. London.154: 377‐402. [5]. Russell MJ. 2007. The Alkaline Solution to the Emergence of Life: Energy, Entropy and Early Evolution. Acta Biotheoretica doi:10.1007/s10441‐007‐9018‐5. |
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