How did life begin on the early Earth? We know that life today is driven by the universal laws of chemistry and physics. By applying these laws over the past ?fty years, en- mous progress has been made in understanding the molecular mechanisms that are the foundations of the living state. For instance, just a decade ago, the ?rst human genome was published, all three billion base pairs. Using X-ray diffraction data from crystals, we can see how an enzyme molecule or a photosynthetic reaction center steps through its catalytic function. We can even visualize a ribosome, central to all life, translate - netic information into a protein. And we are just beginning to understand how molecular interactions regulate thousands of simultaneous reactions that continuously occur even in the simplest forms of life. New words have appeared that give a sense of this wealth of knowledge: The genome, the proteome, the metabolome, the interactome. But we can’t be too smug. We must avoid the mistake of the physicist who, as the twentieth century began, stated con?dently that we knew all there was to know about physics, that science just needed to clean up a few dusty corners. Then came relativity, quantum theory, the Big Bang, and now dark matter, dark energy and string theory. Similarly in the life sciences, the more we learn, the better we understand how little we really know. There remains a vast landscape to explore, with great questions remaining.

Leading researchers in the area of the origin and evolution of life in the universe contributed to Chemical Evolution: Physics of the Origin and Evolution of Life. This volume provides a review of this interdisciplinary field. In 35 chapters many aspects of the origin of life are discussed by 90 authors, with particular emphasis on the early paleontological record: physical, chemical, biological, and informational aspects of life's origin, instrumentation in exobiology and system exploration; the search for habitable planets and extraterrestrial intelligent radio signals. This book contains the proceedings of the Fourth Trieste Conference on Chemical Evolution that took place in September 1995, in which scientists from a wide geographical distribution joined in a Memorial to Cyril Ponnamperuma, who was a pioneer in the field of chemical evolution, the origin of life, and exobiology, and also initiated the Trieste Conferences on Chemical Evolution and the Origin of Life. This fourth Conference was therefore dedicated to his memory. Audience: Graduate students and researchers in the many areas of basic, earth, and life sciences that contribute to the study of chemical evolution and the origin of life.

The formation of more complex carbon compounds from simple ones through the action of radiation is used in an interpretation of the original formation of such compounds on earth. The relation of plants and animals and evolution of photosynthesis is discussed in the light of the participation of sulfur compounds in the metabolism of both groups.

This book addresses some important open questions in this interdisciplinary field of research. In spite of its broad scope, ranging from the earliest evidence of life on earth to the search for extraterrestrial intelligence, the main focus is on chemical evolution. Once the macromolecules of life were formed, the evolution of the earliest life forms enhanced the importance of chirality. This led to the highly asymmetric environment of the macromolecules of the living cell the hallmark of life itself. The subject of chirality, in particular, is discussed in depth: the status of the weak force as the only true chiral influence is presented. A substantial number of papers review both the theoretical as well as the experimental basis of the origin of biochirality. A second broad area discussed in detail is the RNA world. Some successes of this hypothesis are highlighted; the hierarchy of previous evolutionary stages leading to the origin of life, such as the pyrophosphate world, are considered. The question is raised whether useful hints may still be inferred from molecular fossils existing in contemporary cells. Contents The Origin, Evolution, and Distribution of Life in the Universe C. Ponnamperuma Chemical Origin and Early Evolution of Biological Energy Conversion H. Baltscheffsky Phosphate in Models for Chemical Evolution G. Arrhenius, B. Gedulin and Mojzsis Evolution in an RNA World P. Schuster Small Pathogenic RNAs of Plants: Living Fossils of the RNA World? T.O. Diener The Weak Force and the Origin of Life A.J. MacDermott The Origin of Chirality, the Role of Phase Transitions and Their Induction in Amino Acids A. Salam Spontaneous Regulating Mechanisms That May Have Led to the Origin of Life J. Chela-Flores Chirality and the Origin of Life R. Navarro Gonzalez, R.K. Khanna and C. Ponnamperuma >Search for Phase Transitions Changing Molecular Chirality A. Figureau, E. Duval and A. Boukenter Theoretical and Experimental Studies on the Possibility of Chirality Dependent Time Direction in Molecules A.S. Garay Extraterrestrial Intelligences J. Heidmann Discussion Sessions Biochemical Markers in Precambian Sediments--Indian Subcontinent S.S. Rane, A.V. Patankar, M.S. Chadha, B. Udayraj and S.M. Naqvi Practicabilities and Limits of Stereospecific Autocatalysis: An Experimental Approach T. Buhse, W. Thiemann, D. Lavabre and J.-C. Micheau Ionizing Radiation and Chemical Processing of Waters on Early Earth I.G. Draganic and S.I. Vujosevic Chemical Effects of Ionizing Radiation and Sonic Energy in the Context of Chemical Evolution A. Negron-Mendoza and G. Albarran Differences in Radiolysis Behavior of D,L-Amino Acid in Primary Stage and Thermodynamic Equilibrium State W.Q. Wang, J.L. Wu and J. Jiang Experimental Searches for the Origin of Biomolecular Asymmetry L. Keszthelyi True and False Chirality L.D. Barron Chiral Interaction and Biomolecular Evolution G. Gilat Chiral Forces and Molecular Dissymmetry R. Mohan Viroids and Viruses at the Origin of Organized Life L.J. Boya and P. Boya The Role of Neoteny and Sociogenesis in the Evolution of Cell Structure V.J.A. Novak

This symposium was held at the NASA Ames Research Center, Moffett Field, California July 24-27, 1990. The NASA Exobiology principal investigators reported their recent research findings. Scientific papers were presented in the following areas: cosmic evolution of biogenic compounds, prebiotic evolution (planetary and molecular), early evolution of life (biological and geochemical), evolution of advanced life, solar system exploration, and the Search for Extraterrestrial Intelligence (SETI).

This interdisciplinary book consists of the proceedings of the Alexander Ivanovich Oparin lOOth Anniversary Conference, The Third Trieste Conference on Chemical Evolution, which took place at the International Centre for Theoretical Physics from 29 August till 2 September, 1994. A general overview of Oparin's life and work is followed by a review of Alfonso Herera, another pioneer in the studies of the origin of life. The subject matter is organized in ten sections corresponding to various aspects of our current understanding of the subject that was initiated by Oparin. These subjects were covered by fifty three speakers. There were sixty seven participants from a wide geographical distribution; twenty seven countries were represented. We have included the invited lecture of Professor Igor Kulaev, who was unable to be present at the conference for reasons beyond his control. The conference was generously supported by the International Centre for Theoretical Physics, the Commission of the European Communities, the International Centre for Genetic Engineering and Biotechnology, the International Centre for Science and High Technology, and UNESCO. Cyril Ponnamperuma, University of Maryland, U.S.A. Julian Chela-Flores, ICTP, Italy, and IDEA, Venezuela. xi FOREWORD As this volume was going to press we learnt of the untimely death of Cyril Ponnamperuma who died of cardiac arrest on December 20, 1994.

The field of planetary biology and chemical evolution draws together experts in astronomy, paleobiology, biochemistry, and space science who work together to understand the evolution of living systems. This field has made exciting discoveries that shed light on how organic compounds came together to form self-replicating molecules-the origin of life. This volume updates that progress and offers recommendations on research programs-including an ambitious effort centered on Mars-to advance the field over the next 10 to 15 years. The book presents a wide range of data and research results on these and other issues: The biogenic elements and their interaction in the interstellar clouds and in solar nebulae. Early planetary environments and the conditions that lead to the origin of life. The evolution of cellular and multicellular life. The search for life outside the solar system. This volume will become required reading for anyone involved in the search for life's beginnings-including exobiologists, geoscientists, planetary scientists, and U.S. space and science policymakers.

Leading researchers in the area of the origin, evolution and distribution of life in the universe contributed to Exobiology: Matter, Energy, and Information in the Origin and Evolution of Life in the Universe. This volume provides a review of this interdisciplinary field. In 50 chapters many aspects that contribute to exobiology are reviewed by 90 authors. These include: historical perspective of biological evolution; cultural aspects of exobiology, cosmic, chemical and biological evolution, molecular biology, geochronology, biogeochemistry, biogeology, and planetology. Some of the current missions are discussed. Other subjects in the frontier of exobiology are reviewed, such as the search for planets outside the solar system, and the possible manifestation of intelligence in those new potential environments. The SETI research effort is well represented in this general overview of exobiology. This book is the proceedings of the Fifth Trieste Conference on Chemical Evolution that took place in September 1997. The volume is dedicated to the memory of Nobel Laureate Abdus Salam who suggested the initiation of the Trieste conferences on chemical evolution and the origin of life. Audience: Graduate students and researchers in the many areas of basic, earth, and life sciences that contribute to the study of chemical evolution and the origin, evolution and distribution of life in the universe.

Here is a fascinating reader-friendly exploration of “the phosphorus enigma.” The volume attempts to answer the questions: How did phosphorus atoms, which are produced inside the inner cores of a handful of huge stars, become concentrated in relatively high proportions in the organisms composing Earth’s biosphere? And how did these phosphate derivatives manage to be included in such a great variety of organic molecules playing essential biochemical roles in all known life forms? Due to the interdisciplinary nature of the topic, the volume is arranged in three sections. The first section introduces the fundamental concepts and notions of physics, chemistry, and biology necessary for the proper understanding of the topics discussed within an astronomical framework. The author then focuses on the role of phosphorus and its compounds within the context of chemical evolution in galaxies, considering its relevance in most essential biochemical functions as well as its peculiar chemistry under different physicochemical conditions. The third section provides an overall perspective on the role of phosphorus and its compounds in current areas of research of solid state physics, materials engineering, nanotechnology or medicine.