A more comprehensive version of evolutionary theory that focuses as much on the origin of biological form as on its diversification. The field of evolutionary biology arose from the desire to understand the origin and diversity of biological forms. In recent years, however, evolutionary genetics, with its focus on the modification and inheritance of presumed genetic programs, has all but overwhelmed other aspects of evolutionary biology. This has led to the neglect of the study of the generative origins of biological form. Drawing on work from developmental biology, paleontology, developmental and population genetics, cancer research, physics, and theoretical biology, this book explores the multiple factors responsible for the origination of biological form. It examines the essential problems of morphological evolution—why, for example, the basic body plans of nearly all metazoans arose within a relatively short time span, why similar morphological design motifs appear in phylogenetically independent lineages, and how new structural elements are added to the body plan of a given phylogenetic lineage. It also examines discordances between genetic and phenotypic change, the physical determinants of morphogenesis, and the role of epigenetic processes in evolution. The book discusses these and other topics within the framework of evolutionary developmental biology, a new research agenda that concerns the interaction of development and evolution in the generation of biological form. By placing epigenetic processes, rather than gene sequence and gene expression changes, at the center of morphological origination, this book points the way to a more comprehensive theory of evolution.

Today's biodiversity is the spectacular product of hundreds of millions of years of evolution. Understanding how this diversity of living organisms appeared is one of the most intriguing and challenging question in biology. Because organismal morphology is established during embryonic development, and because morphological traits diversified from ancestral forms during evolution, it can be inferred that changes in the mechanisms controlling embryonic development are instrumental for morphological evolution. This syllogism lies at the very heart of a new discipline called Evo-Devo which is centered in the identification of the cellular and genetic mechanisms that, through modifications in developmental programmes, were at the base of morphological innovations during evolution. After the discovery of the broad conservation of gene content and regulatory networks in the animal kingdom, as well as in plants, Evo-Devo is orienting towards the study of differences through experimental and functional approaches. Given the wide range of species, gene families, and developmental processes considered, a concerted effort is still required to shed light on the genetic, cellular and molecular mechanisms involved in phenotypic evolution. It is a particularly exciting time for this field of evolutionary developmental biology, as the advent of novel imaging, genome editing and sequencing technologies allows the study of almost any organism in ways that were unthinkable only a few years ago. Therefore, the aim of this Frontiers Research Topic is to gather an original collection of experimental approaches, concepts and hypotheses reflecting the current diversity of the Evo-Devo field. We have organized the articles according to the mechanistic depth with which they tackle specific evolutionary issues. Hence, comparisons of expression patterns have been grouped in Chapter 1, changes in regulatory interactions and gene networks are presented in Chapter 2, while Chapter 3 focuses on the evolution of developmental processes and biological patterns.

Today's biodiversity is the spectacular product of hundreds of millions of years of evolution. Understanding how this diversity of living organisms appeared is one of the most intriguing and challenging question in biology. Because organismal morphology is established during embryonic development, and because morphological traits diversified from ancestral forms during evolution, it can be inferred that changes in the mechanisms controlling embryonic development are instrumental for morphological evolution. This syllogism lies at the very heart of a new discipline called Evo-Devo which is centered in the identification of the cellular and genetic mechanisms that, through modifications in developmental programmes, were at the base of morphological innovations during evolution. After the discovery of the broad conservation of gene content and regulatory networks in the animal kingdom, as well as in plants, Evo-Devo is orienting towards the study of differences through experimental and functional approaches. Given the wide range of species, gene families, and developmental processes considered, a concerted effort is still required to shed light on the genetic, cellular and molecular mechanisms involved in phenotypic evolution. It is a particularly exciting time for this field of evolutionary developmental biology, as the advent of novel imaging, genome editing and sequencing technologies allows the study of almost any organism in ways that were unthinkable only a few years ago. Therefore, the aim of this Frontiers Research Topic is to gather an original collection of experimental approaches, concepts and hypotheses reflecting the current diversity of the Evo-Devo field. We have organized the articles according to the mechanistic depth with which they tackle specific evolutionary issues. Hence, comparisons of expression patterns have been grouped in Chapter 1, changes in regulatory interactions and gene networks are presented in Chapter 2, while Chapter 3 focuses on the evolution of developmental processes and biological patterns.

This book proposes a new way to think about evolution. The author carefully brings together evidence from diverse fields of science. In the process, he bridges the gaps between many different--and usually seen as conflicting--ideas to present one integrative theory named ONCE, which stands for Organic Nonoptimal Constrained Evolution. The author argues that evolution is mainly driven by the behavioral choices and persistence of organisms themselves, in a process in which Darwinian natural selection is mainly a secondary--but still crucial--evolutionary player. Within ONCE, evolution is therefore generally made of mistakes and mismatches and trial-and-error situations, and is not a process where organisms engage in an incessant, suffocating struggle in which they can't thrive if they are not optimally adapted to their habitats and the external environment. Therefore, this unifying view incorporates a more comprehensive view of the diversity and complexity of life by stressing that organisms are not merely passive evolutionary players under the rule of external factors. This insightful and well-reasoned argument is based on numerous fascinating case studies from a wide range of organisms, including bacteria, plants, insects and diverse examples from the evolution of our own species. The book has an appeal to researchers, students, teachers, and those with an interest in the history and philosophy of science, as well as to the broader public, as it brings life back into biology by emphasizing that organisms, including humans, are the key active players in evolution and thus in the future of life on this wonderful planet.

In the final decades of the twentieth century, the advent of evolutionary developmental biology (evo-devo) offered a revolutionary new perspective that transformed the classical neo-Darwinian, gene-centered study of evolution. In The Architecture of Evolution, Marco Tamborini demonstrates how this radical innovation was made possible by the largely forgotten study of morphology. Despite the key role morphology played in the development of evolutionary biology since the 1940s, the architecture of organisms was excluded from the Modern Evolutionary Synthesis. And yet, from the beginning of the twentieth century to the 1970s and ’80s, morphologists sought to understand how organisms were built and how organismal forms could be generated and controlled. The generation of organic form was, they believed, essential to understanding the mechanisms of evolution. Tamborini explores how the development of evo-devo and the recent organismal turn in biology involved not only the work of morphologists but those outside the biological community with whom they exchanged their data, knowledge, and practices. Together with architects and engineers, they worked to establish a mathematical and theoretical basis for the study of organic form as a mode of construction, developing and reinterpreting important notions that would play a central role in the development of evolutionary developmental biology in the late 1980s. This book sheds light not only on the interdisciplinary basis for many of the key concepts in current developmental biology but also on contributions to the study of organic form outside the English-speaking world.

Leading researchers in evolutionary developmental biology seek linkages between, and a synthesis of, development, physiology, endocrinology, ecology, and evolution. Evolutionary developmental biology, also known as evo-devo or EDB, seeks to find links between development and evolution by opening the "black box" of development's role in evolution and in the evolution of developmental mechanisms. In particular, this volume emphasizes the roles of the environment and of hormonal signaling in evo-devo. It brings together a group of leading researchers to analyze the dynamic interaction of environmental factors with developmental and physiological processes and to examine how environmental signals are translated into phenotypic change, from the molecular and cellular level to organisms and groups of organisms. Taken together, these chapters demonstrate the crucial roles of those processes of genetic, developmental, physiological, and hormonal change that underpin evolutionary change in development, morphology, physiology, behavior, and life-history. Part I investigates links between environmental signals and developmental processes that could be preserved over evolutionary time. Several contributors evaluate the work of the late Ryuichi Matsuda, especially his emphasis on the role of the external environment in genetic change and variability ("pan-environmentalism"). Other contributors in part I analyze different aspects of environmental-genetic-evolutionary linkages, including the importance of alternate ontogenies in evolution and the paradox of stability over long periods of evolutionary time. Part II examines the plasticity that characterizes much of development, with contributors discussing such topics as gene regulatory networks and heterochronicity. Part III analyzes the role of hormones and metamorphosis in the evolution of such organisms with alternate life-history stages as lampreys, amphibians, and insects.