Chemical Evolution [antikvár]

PREFACE The lectures upon which this book is based had their beginnings in 1949 during a period of recuperation after an illness. As for most men, musings on the beginnings of man had long played a part in my thoughts, but during this particular period they became focused. After this, pieces of the puzzle of the beginnings of man and, beyond this, the beginnings of life itself became increasingly open to extended evaluation and experiment. The tools of chemistry and physics were developing in precision, and concepts of biochemistry and biology were evolving in generality, so that investigations into the earliest period—that borderland between the non-living and the living—became possible. From the earliest of the modern experimental observations, beginning in 1950, has grown a large body of knowledge from laboratory experiments and from observation in the field. A realm of thought that had only recently been largely speculative, or philosophical, has now become one of scientific investigation and the chief occupation of a large number of experimental and observational scientists. The study of chemical evolution is based upon the assumption that life appeared on the surface of the earth as a result of the normal operation of the laws of physics and chemistry. This implies that there must have been a period of time in the earth's history that encompassed the transition between a non-living molecular population on its surface and a population of molecular aggregates that we would call living. The two approaches used in this book to try to determine the nature of that transition and interface are those of molecular palaeontology—that is, the look backwards in the historical record—and the construction of hypothetical chemical systems that could give rise to living organisms. This is a very personal essay, based largely upon work done in our laboratories, although, of course, it calls also upon the relevant information that has appeared elsewhere. It is not an exhaustive documentary account of the subject. For the past half-dozen years my colleagues and I have been discussing, both publicly and privately, various aspects of the problem of the origin of life, and of man, and it had been my growing hope that some opportunity would present itself that would enable me to record in some more durable form the results of these discussions, as well as some observations. This opportunity came during my year as Eastman