Principles of Evolution: From the Planck Epoch to Complex Multicellular Life (The Frontiers Collection)
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With contributions from a team of leading experts, this volume provides a comprehensive survey of recent achievements in our scientific understanding of evolution. The questions it asks concern the beginnings of the universe, the origin of life and the chances of its arising at all, the role of contingency, and the search for universal features in the plethora of evolutionary phenomena. Rather than oversimplified or premature answers, the chapters provide a clear picture of how these essential problems are being tackled, enabling the reader to understand current thinking and open questions. The tools employed stem from a range of disciplines including mathematics, physics, biochemistry and cell biology. Self-organization as an overarching concept is demonstrated in the most diverse areas: from galaxy formation in the universe to spindle and aster formation in the cell. Chemical master equations, population dynamics, and evolutionary game theory are presented as suitable frameworks for understanding the universal mechanisms and organizational principles observed in a wide range of living units, ranging from cells to societies. This book will provide engaging reading and food for thought for all those seeking a deeper understanding of the science of evolution.
recognizes that the tunneling proposal leads to a wave function different from the no-boundary condition. Consequences of this difference arise, for example, if one asks for the probability of an inflationary phase to occur in the early universe: whereas the tunneling proposal seems to favor the occurrence of such a phase, the no-boundary proposal seems to disfavor it. No final word on this issue has, however, been spoken. It is interesting that the tunneling proposal allows the possibility that
origin of life , initially at least, some nonequilibrium condition has to be supplied externally. Indeed, it is natural that there exists some nonequilibrium condition in nature, as, for example, is provided by a thermal vent. Then, a nonequilibrium condition supplied exogenously is embedded into the internal dynamics so that the relaxation is hindered and the activity is maintained endogenously. Furthermore, we may expect mutual reinforcement between the sustainment of nonequilibrium
[32–35]. Note that in the model, the network and parameters are identical over cells, and in the experiment, isogenic bacteria are used. Nonetheless, there exist large phenotypic fluctuations, that is, the concentration of molecules exhibits a rather large variance over isogenic cells. Here, we discuss the relevance of such fluctuations to evolution, in relation to genotype–phenotype mapping. Often, stochasticity in gene expression is thought to be an obstacle in tuning a system to achieve and
steps or survive for a large number of branching steps. The distribution of the number of offspring generated from a single ancestor is nontrivial, which is often referred to as the cluster size distribution. When the branching probability is given as , the distribution of s-size clusters follows a power law , where the exponent τ is given as (15.4) for the critical branching tree. 15.2.2 Fractality Fractal scaling refers to a power-law relationship between the minimum number of boxes
described in terms of catalytic reaction networks. In the first part of his contribution, Kaneko discusses three types of catalytic reaction networks as an attempt to bridge the gap between chemistry and biology, where biology is represented by a reproducing cell. The approach is again in the spirit of reductionism. All properties that are assumed to be irrelevant for an observed qualitative behavior are stripped off so that the models for the protocells do not even intend to be realistic, or to