Origins of Life and Evolution of Biospheres 

About: Origins of Life and Evolution of Biospheres is an academic journal published by Springer Science+Business Media. The journal publishes majorly in the area(s): Amino acid & Genetic code. It has an ISSN identifier of 0169-6149. Over the lifetime, 2117 publications have been published receiving 48440 citations.

The lipid world.

Abstract: The continuity of abiotically formed bilayer membraneswith similar structures in contemporary cellular life,and the requirement for microenvironments in whichlarge and small molecules could be compartmentalized, support the idea that amphiphilic boundary structurescontributed to the emergence of life. As an extensionof this notion, we propose here a `Lipid World'scenario as an early evolutionary step in theemergence of cellular life on Earth. This conceptcombines the potential chemical activities of lipidsand other amphiphiles, with their capacity to undergospontaneous self-organization into supramolecularstructures such as micelles and bilayers. Inparticular, the documented chemical rate enhancementswithin lipid assemblies suggest that energy-dependentsynthetic reactions could lead to the growth andincreased abundance of certain amphiphilic assemblies.We further propose that selective processes might acton such assemblies, as suggested by our computersimulations of mutual catalysis among amphiphiles. Asdemonstrated also by other researchers, such mutualcatalysis within random molecular assemblies couldhave led to a primordial homeostatic system displayingrudimentary life-like properties. Taken together,these concepts provide a theoretical framework, andsuggest experimental tests for a Lipid World model forthe origin of life.

The origin and amplification of biomolecular chirality

Abstract: t. Chirality and Chiral Homogeneity in Nature 2. Biotic Theories 3. Abiotic Theories 3.1. Chance Mechanisms 3.1.1. Models for Spontaneous Symmetry Breaking 3.1.2. Spontaneous Resolution on Crystallization 3.1.3.Asymmetric Syntheses in Chiral Crystals 3.1.4. Asymmetric Adsorption and Catalysis on Quartz 3.1.5.Asymmetric Adsorption and Polymerization on Clays 3.1.6. Conclusions 3.2. Determinate Mechanisms 3.2.1. Regional and/or Temporal Processes 3.2.1.1.Electric, Magnetic and Gravitational Fields 3.2.1.2.Circularly Polarized Eight 3.2.1.2.1.Asymmetric Photoequilibration 3.2.1.2.2.Photochemical Asymmetric Synthesis 3.2.1.2.3.Asymmetric Photolysis 3.2.1.2.4.Sources of Circularly Polarized Eight 3.2.2. Universal Processes 3.2.2.l.The Violation of Parity 3.2.2.2.The Vester-Ulbricht (V-U) ttypothesis 3.2.2.3.Radioracemization 3.2.2.4.Direct Effects of Chiral Particles 3.2.2.4.1 .Electrons 3.2.2.4.2.Protons 3.2.2.4.3.Positrons and Muons 3.2.2.5.Weak Interactions, Neutral Currents and Parity Violating Energy Differences 3.2.3. Conclusions 4. The Amplification of Enantiomeric Excesses

Submarine hydrothermal vents and associated gradient environments as sites for the origin and evolution of life

Abstract: Submarine hydrothermal vents are the only comtemporary geological environment which may be called truly primeval; they continue to be a major source of gases and dissolved elements to the modern ocean as they were to the Archean ocean. Then, as now, they encompassed a multiplicity of physical and chemical gradients as a direct result of interactions between extensive hydrothermal activity in the Earth's crust and the overlying oceanic and atmospheric environments. We have proposed that these gradients provided the necessary multiple pathways for the abiotic synthesis of chemical compounds, origin and evolution of ‘precells’ and ‘precell’ communities and, ultimately, the evolution of free-living organisms. This hypothesis is consistent with the tectonic, paleontological, and degassing history of the earth and with the use of thermal energy sources in the laboratory to synthesize amino acids and complex organic compounds. In this paper, we expand upon the geophysical, chemical, and possible microbiological analogies between contemporary and Archean hydrothermal systems and suggest several hypotheses, related to our model for the origin and evolution of life at Archean vents, which can be tested in present-day hydrothermal systems.

Lipid synthesis under hydrothermal conditions by Fischer-Tropsch-type reactions.

Abstract: Ever since their discovery in the late 1970's, mid-ocean-ridge hydrothermal systems have received a great deal of attention as a possible site for the origin of life on Earth (and environments analogous to mid-ocean-ridge hydrothermal systems are postulated to have been sites where life could have originated or Mars and elsewhere as well) Because no modern-day terrestrial hydrothermal systems are free from the influence of organic compounds derived from biologic processes, laboratory experiments provide the best opportunity for confirmation of the potential for organic synthesis in hydrothermal systems Here we report on the formation of lipid compounds during Fischer-Tropsch-type synthesis from aqueous solutions of formic acid or oxalic acid Optimum synthesis occurs in stainless steel vessels by heating at 175 degrees C for 2-3 days and produces lipid compounds ranging from C2 to > C35 which consist of n-alkanols, n-alkanoic acids, n-alkenes, n-alkanes and alkanones The precursor carbon sources used are either formic acid or oxalic acid, which disproportionate to H2, CO2 and probably CO Both carbon sources yield the same lipid classes with essentially the same ranges of compounds The synthesis reactions were confirmed by using 13C labeled precursor acids

Adsorption and Polymerization of Amino Acids on Mineral Surfaces: A Review

Abstract: The present paper offers a review of recent (post-1980) work on amino acid adsorption and thermal reactivity on oxide and sulfide minerals. This review is performed in the general frame of evaluating Bernal’s hypothesis of prebiotic polymerization in the adsorbed state, but written from a surface scientist’s point of view. After a general discussion of the thermodynamics of the problem and exactly what effects surfaces should have to make adsorbed-state polymerization a viable scenario, we examine some practical difficulties in experimental design and their bearing on the conclusions that can be drawn from extant works, including the relevance of the various available characterization techniques. We then present the state of the art concerning the mechanisms of the interactions of amino acids with mineral surfaces, including results from prebiotic chemistry-oriented studies, but also from several different fields of application, and discuss the likely consequences for adsorption selectivities. Finally, we briefly summarize the data concerning thermally activated amide bond formation of adsorbed amino acids without activating agents. The reality of the phenomenon is established beyond any doubt, but our understanding of its mechanism and therefore of its prebiotic potential is very fragmentary. The review concludes with a discussion of future work needed to fill the most conspicuous gaps in our knowledge of amino acids/mineral surfaces systems and their reactivity.