Cosmochemical Evolution and the Origins of Life : Proceedings of the Fourth International Conference on the Origin of Life and the First Meeting of the International Society for the Study of the Origin of Life, Barcelona, June 25–28, 1973 Volume II: Contr

For almost 20 years laboratory experiments have advanced the concepts of chemical evolution, particularly with regard to formation of the amino acids. What has been generally lacking is concrete natural evidence for this chemical evolution hypothesis. The recent development of sophisticated analytical techniques and availability of carbonaceous chondrites with a minimum of terrestrial contamination has resulted in the identification of amino acids which provide strong evidence for a natural extraterrestrial chemical synthesis. Since the initial find in the Murchison meteorite (a type II carbonaceous chondrite) of both protein and nonprotein amino acids and amino acids with nearly equal abundances of D and L isomers, further studies have been carried out. These studies have revealed the presence of at least 35 amino acids; the population consists of a wide variety of linear, cyclic and polyfunctional amino acids which shows a trend of decreasing concentration with increasing carbon number. Investigations of the Murray meteorite (a type II carbonaceous chondrite) has produced similar results, but studies of the Orgueil meteorite (a type I carbomiceous chondrite) show only a limited suite of amino acids, some of which appear to be indigenous while others appear to be terrestrial contaminants. A sample of the Murchison meteorite was extracted with D 2 0 and in addition to 'free' amino acids, showing no deuterium incorporation, some amino acids showed the presence of deuterium suggesting either a 'precursor(s)' or hydrogendeuterium exchange which require(s) formation of carbon-hydrogen bonds. Front Matter....Pages I-VII Front Matter....Pages 1-1 Amino Acids in Carbonaceous Chondrites....Pages 3-8 Remarks on the Chemical Conditions on the Surface of the Primitive Earth and the Probability of the Evolution of Life....Pages 9-13 Molten Earth and the Origin of Prebiological Molecules....Pages 15-21 Soil and Water and Its Relationship to the Origin of Life....Pages 23-36 Microbial Contributions to the Evolution of the ‘Steady State’ Carbon Dioxide System....Pages 37-44 Structures of Biogenic Origin from Early Precambrian Rocks of Euro-Asia....Pages 45-57 Front Matter....Pages 59-59 Photochemical Synthesis of Simple Organic Free Radicals on Simulated Planetary Surfaces - an ESR Study....Pages 61-73 High Frequency Discharge Experiment....Pages 75-81 Formation of Prebiochemical Compounds in Models of the Primitive Earth’s Atmosphere....Pages 83-90 Formation of Prebiochemical Compounds in Models of the Primitive Earth’s Atmosphere....Pages 91-97 Organic Synthesis by Quench Reactions....Pages 99-107 Shock Synthesis of Amino Acids II....Pages 109-115 Quantum Chemical Study of the Thermodynamics, Kinetics of Formation and Bonding of H 2 CN: Relevance to Prebiotic Chemistry....Pages 117-125 Aminonitriles: Possible Role in Chemical Evolution....Pages 127-136 Front Matter....Pages 137-137 Macromolecules and the Origin of Life....Pages 139-146 NMR Studies of Prebiotic Polypeptides....Pages 147-153 The Origin of Proteins: Heteropolypeptides from Hydrogen Cyanide and Water....Pages 155-162 Prebiotic Nucleotide Synthesis-Demonstration of a Geologically Plausible Pathway....Pages 163-168 Models of Prebiological Phosphorylation....Pages 169-174 Conditions of Occurrence for Primeval Processes of Transphosphorylations....Pages 175-183 Front Matter....Pages 185-185 Experiments on the Origins of Optical Activity....Pages 187-194 A Technique for the Determination of Enantiomeric Amino Acids in Biological Samples....Pages 195-202 Coacervate-Like Microspheres from Lysine-Rich Proteinoid....Pages 203-209 Evolution in Bioids: Hypercompetitivity as a Source of Bistability and a Possible Role of Metal Complexes as Prenucleoprotic Mediators of Molecular Asymmetry....Pages 211-218 Entropy of the Genetic Information and Evolution....Pages 219-227 Physical Foundations of the Probability of Biogenesis....Pages 229-237 Some Physical Parameters Controlling Cell Size During the Evolution of the Procaryons....Pages 239-243 Front Matter....Pages 245-245 The Beginning of Photosynthesis....Pages 247-251 Evolution of Photosystems of Photosynthetic Organisms....Pages 253-256 Evolution of Oxygen by Plants in Relation to Biosphere Evolution....Pages 257-263 Ambiguity in the Interpretation of Abiotic Syntheses....Pages 265-267 On the Question of the Origin and Evolution of the Genetic System....Pages 269-271 A Model for the Coevolution of the Genetic Code and the Process of Protein Synthesis: Review and Assessment....Pages 273-283 Front Matter....Pages 285-285 Hot Hydrogen Atoms: Initiators of Reactions of Interest in Interstellar Chemistry and Evolution....Pages 287-293 Role of Weak Bases on the Prebiotic Formation of Heterocyclic Compounds....Pages 295-299 The Prebiotic Synthesis of Deoxythymidine Oligonucleotides....Pages 301-308 A Possible Step in the Origin of the Genetic Code....Pages 309-314 The Emergence of Carcinogens During the Evolution of Living Systems....Pages 315-323 Back Matter....Pages 325-334 Proceedings of the Fourth International Conference on the Origin of Life and the First Meeting of the International Society for the Study of the Origin of Life (ISSOL), Barcelona, June 25-28, 1973. Vol. II: Contributed Papers