The book integrates our understanding of the factors and processes underlying the evolution of multicellularity by providing several complementary perspectives (both theoretical and experimental) and using examples from various lineages in which multicellularity evolved. Recent years marked an increased interest in understanding how and why these transitions occurred, and data from various fields are providing new insights into the forces driving the several independent transitions to multicellular life as well as into the genetic and molecular basis for the evolution of this phenotype. The ultimate goal of this book is to facilitate the identification of general and unifying principles and mechanisms.
During evolution there have been several major changes in the way genetic information is organized and transmitted from one generation to the next. These transitions include the origin of life itself, the first eukaryotic cells, reproduction by sexual means, the appearance of multicellular plants and animals, the emergence of cooperation and of animal societies. This is the first book to discuss all these major transitions and their implications for our understanding of evolution.Clearly written and illustrated with many original diagrams, this book will be welcomed by students and researchers in the fields of evolutionary biology, ecology, and genetics.
Among the most important innovations in the history of life is the transition from single-celled organisms to more complex, multicellular organisms. Multicellularity has evolved repeatedly across the tree of life, resulting in the evolution of new kinds of organisms that collectively constitute a significant portion of Earth’s biodiversity and have transformed the biosphere. This volume examines the origins and subsequent evolution of multicellularity, reviewing the types of multicellular groups that exist, their evolutionary relationships, the processes that led to their evolution, and the conceptual frameworks in which their evolution is understood. This important volume is intended to serve as a jumping-off point, stimulating further research by summarizing the topics that students and researchers of the evolution of multicellularity should be familiar with, and highlighting future research directions for the field.
Drawing on recent advances in evolutionary biology, prominent scholars return to the question posed in a pathbreaking book: how evolution itself evolved. In 1995, John Maynard Smith and Eörs Szathmáry published their influential book The Major Transitions in Evolution. The "transitions" that Maynard Smith and Szathmáry chose to describe all constituted major changes in the kinds of organisms that existed but, most important, these events also transformed the evolutionary process itself. The evolution of new levels of biological organization, such as chromosomes, cells, multicelled organisms, and complex social groups radically changed the kinds of individuals natural selection could act upon. Many of these events also produced revolutionary changes in the process of inheritance, by expanding the range and fidelity of transmission, establishing new inheritance channels, and developing more open-ended sources of variation. Maynard Smith and Szathmáry had planned a major revision of their work, but the death of Maynard Smith in 2004 prevented this. In this volume, prominent scholars (including Szathmáry himself) reconsider and extend the earlier book's themes in light of recent developments in evolutionary biology. The contributors discuss different frameworks for understanding macroevolution, prokaryote evolution (the study of which has been aided by developments in molecular biology), and the complex evolution of multicellularity.
The concept of fitness has long been a topic of intense debate among evolutionary biologists and their critics, with its definition and explanatory power coming under attack. In this book, Richard Michod offers a fresh, dynamical interpretation of evolution and fitness concepts. He argues that evolution has no enduring products; what matters is the process of genetic change. Whereas many biologists have focused on competition and aggression as determining factors in survival, Michod, by concentrating on the emergence of individuality at new and more complex levels, finds that cooperation plays even a greater role. Michod first considers the principles behind the hierarchically nested levels of organization that constitute life: genes, chromosomes, genomes, cells, multicellular organisms, and societies. By examining the evolutionary transitions from the molecular level up to the whole organism, the author explains how cooperation and conflict in a multilevel setting leads to new levels of fitness. He builds a model of fitness drawing on recent developments in ecology and multilevel selection theory and on new explanations of the origin of life. Michod concludes with a discussion of the philosophical implications of his theory of fitness, a theory that addresses the most fundamental and unique concept in all of biology.
In 1859 Darwin described a deceptively simple mechanism that he called "natural selection," a combination of variation, inheritance, and reproductive success. He argued that this mechanism was the key to explaining the most puzzling features of the natural world, and science and philosophy were changed forever as a result. The exact nature of the Darwinian process has been controversial ever since, however. Godfrey-Smith draws on new developments in biology, philosophy of science, and other fields to give a new analysis and extension of Darwin's idea. The central concept used is that of a "Darwinian population," a collection of things with the capacity to undergo change by natural selection. From this starting point, new analyses of the role of genes in evolution, the application of Darwinian ideas to cultural change, and "evolutionary transitions" that produce complex organisms and societies are developed. Darwinian Populations and Natural Selection will be essential reading for anyone interested in evolutionary theory
During evolution, there have been several major changes in the way that genetic information is organized and transmitted from one generation to the next. These transitions include the origin of life itself, the first eukaryotic cells, reproduction by sexual means, the appearance of multicellular plants and animals, the emergence of cooperation and of animal societies, and the unique language ability of humans. This is the first book to discuss all of these major transitions. In discussing such a wide range of topics in one volume, the authors are able to highlight the similarities between different transitions - for example, between the union of replicating molecules to form chromosomes and of cells to form multicellular organisms. The authors also show how an understanding of one transition sheds light on others. A common theme in the book is that entities that could replicate independently before the transition can replicate afterwards only as part of a larger whole. Why, then, does selection between entities at the lower level not disrupt selection at the higher level? In answering this question, the authors offer an explanation for the evolution of cooperation at all levels of complexity. Written in a clear style, and illustrated with many original diagrams, this book can be read with enjoyment by anyone with an undergraduate training in the biological sciences. It will be ideal for advanced discussion groups on evolution. Although the content ranges widely from molecular biology to linguistics and from intragenomic conflict to insect societies, no detailed knowledge of any of these topics is required. Mathematical models are clearly explained, and equations and formulae are kept to a minimum.
Are humans a galactic oddity, or will complex life with human abilities develop on planets with environments that remain habitable for long enough? In a clear, jargon-free style, two leading researchers in the burgeoning field of astrobiology critically examine the major evolutionary steps that led us from the distant origins of life to the technologically advanced species we are today. Are the key events that took life from simple cells to astronauts unique occurrences that would be unlikely to occur on other planets? By focusing on what life does - it's functional abilities - rather than specific biochemistry or anatomy, the authors provide plausible answers to this question. Systematically exploring the various pathways that led to the complex biosphere we experience on planet Earth, they show that most of the steps along that path are likely to occur on any world hosting life, with only two exceptions: One is the origin of life itself – if this is a highly improbable event, then we live in a rather “empty universe”. However, if this isn’t the case, we inevitably live in a universe containing a myriad of planets hosting complex as well as microbial life - a “cosmic zoo”. The other unknown is the rise of technologically advanced beings, as exemplified on Earth by humans. Only one technological species has emerged in the roughly 4 billion years life has existed on Earth, and we don’t know of any other technological species elsewhere. If technological intelligence is a rare, almost unique feature of Earth's history, then there can be no visitors to the cosmic zoo other than ourselves. Schulze-Makuch and Bains take the reader through the history of life on Earth, laying out a consistent and straightforward framework for understanding why we should think that advanced, complex life exists on planets other than Earth. They provide a unique perspective on the question that puzzled the human species for centuries: are we alone?
Tackling one of the most difficult and delicate of the evolutionary questions, this challenging book summarizes the more recent results in phylogenetics and developmental biology that address the evolution of key innovations in metazoans. Divided into three sections, the first considers the phylogenetic issues involving this area of the tree of lif
