Biological Evolution And Statistical Physics

This set of lecture notes gives a first coherent account of a novel aspect of the living world that can be called biological information. The book presents both a pedagogical and state-of-the art roadmap of this rapidly evolving area and covers the whole field, from information which is encoded in the molecular genetic code to the description of large-scale evolution of complex species networks. The book will prove useful for all those who work at the interface of biology, physics and information science.

This set of lecture notes gives a first coherent account of a novel aspect of the living world that can be called biological information. The book presents both a pedagogical and state-of-the art roadmap of this rapidly evolving area and covers the whole field, from information which is encoded in the molecular genetic code to the description of large-scale evolution of complex species networks. The book will prove useful for all those who work at the interface of biology, physics and information science.

Analyzes approaches to the study of complexity in the physical, biological, and social sciences.

This concise primer (based on lectures given at summer schools on complex systems and on a masters degree course in complex systems modeling) will provide graduate students and newcomers to the field with the basic knowledge of the concepts and methods of statistical physics and its potential for application to interdisciplinary topics. Indeed, in recent years, statistical physics has begun to attract the interest of a broad community of researchers in the field of complex system sciences, ranging from biology to the social sciences, economics and computer science. More generally, a growing number of graduate students and researchers feel the need to learn some basic concepts and questions originating in other disciplines without necessarily having to master all of the corresponding technicalities and jargon. Generally speaking, the goals of statistical physics may be summarized as follows: on the one hand to study systems composed of a large number of interacting ‘entities’, and on the other to predict the macroscopic (or collective) behavior of the system considered from the microscopic laws ruling the dynamics of the individual ‘entities’. These two goals are, to some extent, also shared by what is nowadays called ‘complex systems science’ and for these reasons, systems studied in the framework of statistical physics may be considered as among the simplest examples of complex systems—allowing in addition a rather well developed mathematical treatment.

This book for physicists, biologists, computer scientists, economists or social scientists shows in selected examples how computer simulation methods which are typical to statistical physics have been applied in other areas outside of physics. Our main part deals with the biology of ageing, while other examples are the functioning of the immune system, the structure of DNA, the fluctuations on the stock market, theories for sociology and for World War II. Are leaky water faucets similar to our heartbeats? Throughout the book we emphasize microscopic models dealing with the action of individuals, whether they are cells of the immune system or traders speculating on the currency market. Complete computer programs are given and explained for biological ageing. The references try to introduce the expert from the covered other fields to the relevant physics literature; and they also show the physicists the way into the biological literature on ageing.

The bulk of this dissertation consists of three separate research projects. Each of them involves models of multi-locus evolution in the context of finite population size, genetic linkage, and both beneficial and deleterious mutations. Each project employs stochastic computer simulations and numerical solutions to equations which approximate a full stochastic model. The first project, presented in chapter two, was conceived as a problem in the field of non-equilibrium statistical physics known as "front propagation'' and was published in Physical Review E. The connection to biological evolution is due to my advisor, Herbert Levine, and his colleagues who pointed out an analogy between diffusive fronts propagating through physical space and a mutating population evolving through fitness space. The second project, presented in chapter three and published in Genetics, is more biologically oriented than the first project. It concerns the evolutionary pressures acting on the rate at which organisms produce spontaneous mutation. Our results agree with experimental data and also make testable predictions. The mathematical methods used are familiar from non-equilibrium statistical physics, but are quite distinct from those used in the first project. The third project, presented in chapter four, is currently being prepared for publication. It concerns the evolutionary advantage of "competence'' for genetic transformation in bacteria, which is conceptually similar to sex. Thus, issues related to the evolution of sex have bearing on this project, and vice versa. A puzzling feature of competence in many species is that normal, vegetatively growing cells stochastically switch in and out of the competence phenotype. We believe that this project provides a novel explanation for this puzzling "mixed strategy.'' A common theme in this dissertation is the drastic effect of having a finite population size N. In each project, the system behaves qualitatively differently in the infinite N limit than for any finite N. Thus, although "mean field theory'' provides helpful approximations in many areas of physics and stochastic processes, it should be used cautiously in evolutionary problems or those with a similar mathematical structure.

This highly interdisciplinary book discusses the phenomenon of life, including its origin and evolution, against the background of thermodynamics, statistical mechanics, and information theory. Among the central themes is the seeming contradiction between the second law of thermodynamics and the high degree of order and complexity produced by living systems. As the author shows, this paradox has its resolution in the information content of the Gibbs free energy that enters the biosphere from outside sources. Another focus of the book is the role of information in human cultural evolution, which is also discussed with the origin of human linguistic abilities. One of the final chapters addresses the merging of information technology and biotechnology into a new discipline — bioinformation technology.This third edition has been updated to reflect the latest scientific and technological advances. Professor Avery makes use of the perspectives of famous scholars such as Professor Noam Chomsky and Nobel Laureates John O'Keefe, May-Britt Moser and Edward Moser to cast light on the evolution of human languages. The mechanism of cell differentiation, and the rapid acceleration of information technology in the 21st century are also discussed.With various research disciplines becoming increasingly interrelated today, Information Theory and Evolution provides nuance to the conversation between bioinformatics, information technology, and pertinent social-political issues. This book is a welcome voice in working on the future challenges that humanity will face as a result of scientific and technological progress.

The Logic of Chance offers a reappraisal and a new synthesis of theories, concepts, and hypotheses on the key aspects of the evolution of life on earth in light of comparative genomics and systems biology. The author presents many specific examples from systems and comparative genomic analysis to begin to build a new, much more detailed, complex, and realistic picture of evolution. The book examines a broad range of topics in evolutionary biology including the inadequacy of natural selection and adaptation as the only or even the main mode of evolution; the key role of horizontal gene transfer in evolution and the consequent overhaul of the Tree of Life concept; the central, underappreciated evolutionary importance of viruses; the origin of eukaryotes as a result of endosymbiosis; the concomitant origin of cells and viruses on the primordial earth; universal dependences between genomic and molecular-phenomic variables; and the evolving landscape of constraints that shape the evolution of genomes and molecular phenomes. "Koonin's account of viral and pre-eukaryotic evolution is undoubtedly up-to-date. His "mega views" of evolution (given what was said above) and his cosmological musings, on the other hand, are interesting reading." Summing Up: Recommended Reprinted with permission from CHOICE, copyright by the American Library Association.