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Origins of Life and Evolution of the Biosphere

Sandra Pizzarello, Everett Shock
The biogenic elements, H, C, N, O, P and S, have a long cosmic history, whose evolution can still be observed in diverse locales of the known universe, from interstellar clouds of gas and dust, to pre-stellar cores, nebulas, protoplanetary discs, planets and planetesimals. The best analytical window into this cosmochemical evolution as it neared Earth has been provided so far by the small bodies of the Solar System, some of which were not significantly altered by the high gravitational pressures and temperatures that accompanied the formation of larger planets and may carry a pristine record of early nebular chemistry...
January 11, 2017: Origins of Life and Evolution of the Biosphere
André Brack
No abstract text is available yet for this article.
December 26, 2016: Origins of Life and Evolution of the Biosphere
David A Baum, Kalin Vetsigian
No abstract text is available yet for this article.
December 8, 2016: Origins of Life and Evolution of the Biosphere
Sabrina Scherer, Eva Wollrab, Luca Codutti, Teresa Carlomagno, Stefan Gomes da Costa, Andreas Volkmer, Amela Bronja, Oliver J Schmitz, Albrecht Ott
We have analyzed the chemical variety obtained by Miller-Urey-type experiments using nuclear magnetic resonance (NMR) spectroscopy and coherent anti-Stokes Raman scattering (CARS) spectroscopy, gas chromatography followed by mass spectrometry (GC/MS) and two-dimensional gas chromatography followed by mass spectrometry (GCxGC/MS). In the course of a running Miller-Urey-type experiment, a hydrophobic organic layer emerged besides the hydrophilic aqueous phase and the gaseous phase that were initially present...
November 28, 2016: Origins of Life and Evolution of the Biosphere
David A Baum, Kalin Vetsigian
Most experimental work on the origin of life has focused on either characterizing the chemical synthesis of particular biochemicals and their precursors or on designing simple chemical systems that manifest life-like properties such as self-propagation or adaptive evolution. Here we propose a new class of experiments, analogous to artificial ecosystem selection, where we select for spontaneously forming self-propagating chemical assemblages in the lab and then seek evidence of a response to that selection as a key indicator that life-like chemical systems have arisen...
November 18, 2016: Origins of Life and Evolution of the Biosphere
Hai Qiao, Na Hu, Jin Bai, Lili Ren, Qing Liu, Liaoqiong Fang, Zhibiao Wang
Protocells are believed to consist of a lipid membrane and encapsulated nucleic acid. As the lipid membrane is impermeable to macromolecules like nucleic acids, the processes by which nucleic acids become encapsulated inside lipid membrane compartments are still unknown. In this paper, a freeze-thaw method was modified and applied to giant unilamellar vesicles (GUVs) and deoxyribonucleic acid (DNA) in mixed solution resulting in the efficient encapsulation of 6.4 kb plasmid DNA and similar length linear DNA into GUVs...
November 2, 2016: Origins of Life and Evolution of the Biosphere
Cristine E A Carneiro, Antonio C Stabile, Frederico P Gomes, Antonio C S da Costa, Cássia T B V Zaia, Dimas A M Zaia
Probably one of the most important roles played by minerals in the origin of life on Earth was to pre-concentrate biomolecules from the prebiotic seas. There are other ways to pre concentrate biomolecules such as wetting/drying cycles and freezing/sublimation. However, adsorption is most important. If the pre-concentration did not occur-because of degradation of the minerals-other roles played by them such as protection against degradation, formation of polymers, or even as primitive cell walls would be seriously compromised...
October 25, 2016: Origins of Life and Evolution of the Biosphere
Alberto Vázquez-Salazar, George Tan, Amanda Stockton, Renato Fani, Arturo Becerra, Antonio Lazcano
The five-membered heterocyclic imidazole group, which is an essential component of purines, histidine and many cofactors, has been abiotically synthesized in different model experiments that attempt to simulate the prebiotic environment. The evolutionary significance of imidazoles is highlighted not only by its presence in nucleic acid components and in histidine, but also by experimental reports of its ability to restore the catalytic activity of ribozymes. However, as of today there are no reports of histidine in carbonaceous chondrites, and although the abiotic synthesis of His reported by Shen et al...
October 22, 2016: Origins of Life and Evolution of the Biosphere
A Kereszturi, L Noack
In this work various factors on the habitability were considered, focusing on conditions irrespective of the central star's radiation, to see the role of specific planetary body related effects. These so called planetary factors were evaluated to identify those trans-domain issues where important information is missing but good chance exit to be filled by new knowledge that might be gained in the next decade(s). Among these strategic knowledge gaps, specific issues are listed, like occurrence of radioactive nucleides in star forming regions, models to estimate the existence of subsurface liquid water from bulk parameters plus evolutionary context of the given system, estimation on the existence of redox gradient depending on the environment type etc...
November 2016: Origins of Life and Evolution of the Biosphere
V Dehant, D Asael, R M Baland, B K Baludikay, J Beghin, J Belza, M Beuthe, D Breuer, S Chernonozhkin, Ph Claeys, Y Cornet, L Cornet, A Coyette, V Debaille, C Delvigne, M H Deproost, N De WInter, C Duchemin, F El Atrassi, C François, J De Keyser, C Gillmann, E Gloesener, S Goderis, Y Hidaka, D Höning, M Huber, G Hublet, E J Javaux, Ö Karatekin, J Kodolanyi, L Lobo Revilla, L Maes, R Maggiolo, N Mattielli, M Maurice, S McKibbin, A Morschhauser, W Neumann, L Noack, L B S Pham, L Pittarello, A C Plesa, A Rivoldini, S Robert, P Rosenblatt, T Spohn, J -Y Storme, N Tosi, A Trinh, M Valdes, A C Vandaele, F Vanhaecke, T Van Hoolst, N Van Roosbroek, V Wilquet, M Yseboodt
The Interuniversity Attraction Pole (IAP) 'PLANET TOPERS' (Planets: Tracing the Transfer, Origin, Preservation, and Evolution of their Reservoirs) addresses the fundamental understanding of the thermal and compositional evolution of the different reservoirs of planetary bodies (core, mantle, crust, atmosphere, hydrosphere, cryosphere, and space) considering interactions and feedback mechanisms. Here we present the first results after 2 years of project work.
November 2016: Origins of Life and Evolution of the Biosphere
Vardan Adibekyan, Pedro Figueira, Nuno C Santos
We used a sample of super-Earth-like planets detected by the Doppler spectroscopy and transit techniques to explore the dependence of orbital parameters of the planets on the metallicity of their host stars. We confirm the previous results (although still based on small samples of planets) that super-Earths orbiting around metal-rich stars are not observed to be as distant from their host stars as we observe their metal-poor counterparts to be. The orbits of these super-Earths with metal-rich hosts usually do not reach into the Habitable Zone (HZ), keeping them very hot and inhabitable...
November 2016: Origins of Life and Evolution of the Biosphere
Karl Kaye, David E Bryant, Katie E R Marriott, Shohei Ohara, Colin W G Fishwick, Terence P Kee
We describe here experiments which demonstrate the selective phospho-transfer from a plausibly prebiotic condensed phosphorus (P) salt, pyrophosphite [H2P2O5(2-); PPi(III)], to the phosphate group of 5'-adenosine mono phosphate (5'-AMP). We show further that this P-transfer process is accelerated both by divalent metal ions (M(2+)) and by organic co-factors such as acetate (AcO(-)). In this specific case of P-transfer from PPi(III) to 5'-AMP, we show a synergistic enhancement of transfer in the combined presence of M(2+) & AcO(-)...
November 2016: Origins of Life and Evolution of the Biosphere
P Figueira, J P Faria, V Zh Adibekyan, M Oshagh, N C Santos
We apply the Bayesian framework to assess the presence of a correlation between two quantities. To do so, we estimate the probability distribution of the parameter of interest, ρ, characterizing the strength of the correlation. We provide an implementation of these ideas and concepts using python programming language and the pyMC module in a very short (∼ 130 lines of code, heavily commented) and user-friendly program. We used this tool to assess the presence and properties of the correlation between planetary surface gravity and stellar activity level as measured by the log([Formula: see text]) indicator...
November 2016: Origins of Life and Evolution of the Biosphere
Illia Zymak, Ján Žabka, Miroslav Polášek, Patrik Španěl, David Smith
Reliable theoretical models of the chemical kinetics of the ionosphere of Saturn's moon, Titan, is highly dependent on the precision of the rates of the reactions of ambient ions with hydrocarbon molecules at relevant temperatures. A Variable Temperature Selected Ions Flow Tube technique, which has been developed primarily to study these reactions at temperatures within the range of 200-330 K, is briefly described. The flow tube temperature regulation system and the thermalisation of ions are also discussed...
November 2016: Origins of Life and Evolution of the Biosphere
Robert Pascal, Addy Pross
In this paper we propose a logical connection between the physical and biological worlds, one resting on a broader understanding of the stability concept. We propose that stability manifests two facets - time and energy, and that stability's time facet, expressed as persistence, is more general than its energy facet. That insight leads to the logical formulation of the Persistence Principle, which describes the general direction of material change in the universe, and which can be stated most simply as: nature seeks persistent forms...
November 2016: Origins of Life and Evolution of the Biosphere
Muriel Gargaud, Wolf Dietrich Geppert, Nigel J Mason
No abstract text is available yet for this article.
November 2016: Origins of Life and Evolution of the Biosphere
I Gomoiu, E Chatzitheodoridis, S Vadrucci, I Walther, R Cojoc
In this study we investigated the security of a spaceflight experiment from two points of view: spreading of dried fungal spores placed on the different wafers and their viability during short and long term missions on the International Space Station (ISS). Microscopic characteristics of spores from dried spores samples were investigated, as well as the morphology of the colonies obtained from spores that survived during mission. The selected fungal species were: Aspergillus niger, Cladosporium herbarum, Ulocladium chartarum, and Basipetospora halophila...
November 2016: Origins of Life and Evolution of the Biosphere
V Mazankova, L Torokova, F Krcma, N J Mason, S Matejcik
This work extends our previous experimental studies of the chemistry of Titan's atmosphere by atmospheric glow discharge. The Titan's atmosphere seems to be similarly to early Earth atmospheric composition. The exploration of Titan atmosphere was initiated by the exciting results of the Cassini-Huygens mission and obtained results increased the interest about prebiotic atmospheres. Present work is devoted to the role of CO2 in the prebiotic atmosphere chemistry. Most of the laboratory studies of such atmosphere were focused on the chemistry of N2 + CH4 mixtures...
November 2016: Origins of Life and Evolution of the Biosphere
J Hrušák, I Paidarová
Methane conversion and in particular the formation of the C-O bond is one of fundamental entries to organic chemistry and it appears to be essential for understanding parts of atmospheric chemistry of Titan, but, in broader terms it might be also relevant for Earth-like exoplanets. Theoretical study of the reactions of methane with atomic oxygen ion in its excited electronic states requires treating simultaneously at least 19 electronic states. Development of a computational strategy that would allow chemically reasonable and computationally feasible treatment of the CH4 (X)/O(+) ((2)D, (2)P) system is by far not trivial and it requires careful examination of all the complex features of the corresponding 19 potential energy surfaces...
November 2016: Origins of Life and Evolution of the Biosphere
Florian Gallet, Corinne Charbonnel, Louis Amard
With about 2000 exoplanets discovered within a large range of different configurations of distance from the star, size, mass, and atmospheric conditions, the concept of habitability cannot rely only on the stellar effective temperature anymore. In addition to the natural evolution of habitability with the intrinsic stellar parameters, tidal, magnetic, and atmospheric interactions are believed to have strong impact on the relative position of the planets inside the so-called habitable zone. Moreover, the notion of habitability itself strongly depends on the definition we give to the term "habitable"...
November 2016: Origins of Life and Evolution of the Biosphere
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