Synopses & Reviews
The now recognized extensive existence of life on earth very shortly after the destructive bombardment of the earth's surface by early solar system debris has stimulated inquiry into possible exogenous sources of prebiotic molecules from space as well as intensified studies of the early earth's atmosphere. The chapters in this book cover the possible sources of prebiotic molecules and avenues by which life could have evolved, starting from the birth and evolution of the solar system. The relevance of the classic experiments by Stanley Miller on the formation of life's building blocks on an early earth is reexamined. The role of chemistry in space is covered by chapters on interstellar dust, and meteorites to which experimental as well as theoretical investigations have been directed. In various chapters the existence of amino acids as well as other prebiotic molecules in meteorites is clearly established and inferred for interstellar dust and comets. Theories of molecular synthesis in the solar nebula are considered. Extensive coverage is given to the physical conditions and to prebiotic systems on the early earth. Possible pathways to life on an early Mars and the possible messages to be obtained by space exploration are discussed. Questions of effects of clays and of chirality on early chemical evolution are discussed. Recent ideas on the RNA world as the precursor to life are reviewed. The open-endedness of the study of life's origins and the need to investigate whether the prebiotic building blocks formed in outer space or on the earth is emphasized. A good deal of the book is suitable to graduate students.
Synopsis
This volume contains the lectures presented at the second course of the International School of Space Chemistry held in Erice (Sicily) from October 20 - 30 1991 at the "E. Majorana Centre for Scientific Culture". The course was attended by 58 participants from 13 countries. The Chemistry of Life's Origins is well recognized as one of the most critical subjects of modem chemistry. Much progress has been made since the amazingly perceptive contributions by Oparin some 70 years ago when he first outlined a possible series of steps starting from simple molecules to basic building blocks and ultimate assembly into simple organisms capable of replicating, catalysis and evolution to higher organisms. The pioneering experiments of Stanley Miller demonstrated already forty years ago how easy it could have been to form the amino acids which are critical to living organisms. However we have since learned and are still learning a great deal more about the primitive conditions on earth which has led us to a rethinking of where and how the condition for prebiotic chemical processes occurred. We have also learned a great deal more about the molecular basis for life. For instance, the existence of DNA was just discovered forty years ago.
Table of Contents
Preface. Interstellar dust evolution: a reservoir of prebiotic molecules; J.M. Greenberg, C.X. Mendoza-Gómez. Laboratory simulations of grain icy mantles processing by cosmic rays; V. Pirronello. Physics and chemistry of protoplanetary accretion disks; W.J. Duschl. Chemistry of the solar nebula; B. Fegley, Jr. Early evolution of the atmosphere and ocean; J.F. Kasting. Origin and evolution of Martian atmosphere and climate and possible exobiological experiments; L.M. Mukhin. The possible pathways of the synthesis of precursors on the early earth; L.M. Mukhin, M.V. Gerasimov. Physical and chemical composition of comets - from interstellar space to the earth; J.M. Greenberg. Organic matter in meteorites: molecular and isotopic analyses of the Murchison meteorite; J.R. Cronin, S. Chang. Prebiotic synthesis in planetary environments; S. Chang. Prebiotic synthesis on minerals: RNA oligomer formation; J.P. Ferris. Biology and theory: RNA and the origin of life; A.W. Schwartz. Chirality and the origins of life; A. Brack. Early proteins; A. Brack. The beginnings of life on earth: evidence from the geological record; M. Schidlowski. Index.