Does natural selection act primarily on individual organisms, on groups, on genes, or on whole species? This book provides a comprehensive analysis of the debate in evolutionary biology over the levels of selection, focusing on conceptual, philosophical and foundational questions.

Does natural selection act primarily on individual organisms, on groups, on genes, or on whole species? This book provides a comprehensive analysis of the debate in evolutionary biology over the levels of selection, focusing on conceptual, philosophical and foundational questions.

Ever since the groundbreaking work of George Williams, W. D. Hamilton, and Richard Dawkins, evolutionary biologists have recognized that natural selection generally does not operate for the good of the group, but rather for the good of lower-level units such as the individual, the cell, even the gene. One of the fundamental problems of biology is: what keeps competition between these various levels of natural selection from destroying the common interests to be gained from cooperation? In this volume twelve prominent scientists explore this question, presenting a comprehensive survey of the current theoretical and empirical research in evolutionary biology. Recent studies show that at many levels of biological organization, mechanisms have evolved to prevent potential conflict in natural selection. Editor Laurent Keller's aim in this book is to bring together leading researchers from all biological disciplines to outline these potential conflicts and discuss how they are resolved. A multi-level approach of this kind allows important insights into the evolution of life, as well as bridging the long-standing conceptual chasm between molecular and organismal biologists. The chapters here follow a rigorous theoretical framework, giving the book an overall synergy that is unique to multi-authored books. The contributors, in addition to the editor, are H. Charles J. Godfray, Edward Allen Herre, Dawn M. Kitchen, Egbert Giles Leigh, Jr., Catherine M. Lessells, Richard E. Michod, Leonard Nunney, Craig Packer, Andrew Pomiankowski, H. Kern Reeve, John Maynard Smith, and Eörs Szathmáry.

Does natural selection act primarily on individual organisms, on groups, on genes, or on whole species? Samir Okasha provides a comprehensive analysis of the debate in evolutionary biology over the levels of selection, focusing on conceptual, philosophical and foundational questions. A systematic framework is developed for thinking about natural selection acting at multiple levels of the biological hierarchy; the framework is then used to help resolve outstanding issues. Considerable attention is paid to the concept of causality as it relates to the levels of selection, in particular the idea that natural selection at one hierarchical level can have effects that 'filter' up or down to other levels. Unlike previous work in this area by philosophers of science, full account is taken of the recent biological literature on 'major evolutionary transitions' and the recent resurgence of interest in multi-level selection theory among biologists. Other biological topics discussed include Price's equation, kin and group selection, the gene's eye view, evolutionary game theory, outlaws and selfish genetic elements, species and clade selection, and the evolution of individuality. Philosophical topics discussed include reductionism and holism, causation and correlation, the nature of hierarchical organization, and realism and pluralism.

This book provides fascinating insights into the development and genetics of evolutionary processes on the basis of animals living in the dark, such as the Astyanax cave fish. Biologically functionless traits show high variability, which results from neutral deleterious mutations no longer being eliminated by natural selection, which normally acts to preserve functional capability. These negative mutations accumulate until the traits they are responsible for become rudimentary or even lost. The random genetic basis of regressive evolution is in accordance with Nei’s Neutral Theory of Molecular Evolution, which applies to the molecular level. Such processes are particularly conspicuous in species living in constant darkness, where, for example in Astyanax, all traits depending on the exposure to light, like eyes, pigmentation, visually triggered aggressive behaviour, negative phototaxis, and several peripheral outcomes of circadian rhythmicity, are useless and diminish. In compensation constructive traits like taste, olfaction or the lateral line senses are improved by selection and do not show variability. Regressive and constructive traits inherit independently, proving that the rudimentation process is not driven by pleiotropic linkage between them. All these traits are subject to mosaic evolution and exhibit unproportional epistatic gene effects, which play an important role in evolutionary adaptation and improvement. Offering valuable evolutionary insights and supplemented by a wealth of illustrations, this book will appeal to evolutionary and developmental biologists alike.

Quantitative traits-be they morphological or physiological characters, aspects of behavior, or genome-level features such as the amount of RNA or protein expression for a specific gene-usually show considerable variation within and among populations. Quantitative genetics, also referred to as the genetics of complex traits, is the study of such characters and is based on mathematical models of evolution in which many genes influence the trait and in which non-genetic factors may also be important. Evolution and Selection of Quantitative Traits presents a holistic treatment of the subject, showing the interplay between theory and data with extensive discussions on statistical issues relating to the estimation of the biologically relevant parameters for these models. Quantitative genetics is viewed as the bridge between complex mathematical models of trait evolution and real-world data, and the authors have clearly framed their treatment as such. This is the second volume in a planned trilogy that summarizes the modern field of quantitative genetics, informed by empirical observations from wide-ranging fields (agriculture, evolution, ecology, and human biology) as well as population genetics, statistical theory, mathematical modeling, genetics, and genomics. Whilst volume 1 (1998) dealt with the genetics of such traits, the main focus of volume 2 is on their evolution, with a special emphasis on detecting selection (ranging from the use of genomic and historical data through to ecological field data) and examining its consequences.

This book embeds a novel evolutionary analysis of human group selection within a comprehensive overview of multilevel selection theory, a theory wherein evolution proceeds at the level of individual organisms and collectives, such as human families, tribes, states, and empires. Where previous works on the topic have variously supported multilevel selection with logic, theory, experimental data, or via review of the zoological literature; in this book the authors uniquely establish the validity of human group selection as a historical evolutionary process within a multilevel selection framework. Select portions of the historical record are examined from a multilevel selectionist perspective, such that clashing civilizations, decline and fall, law, custom, war, genocide, ostracism, banishment, and the like are viewed with the end of understanding their implications for internal cohesion, external defense, and population demography. In doing so, its authors advance the potential for further interdisciplinary study in fostering, for instance, the convergence of history and biology. This work will provide fresh insights not only for evolutionists but also for researchers working across the social sciences and humanities.