Cells Embryos And Evolution

Gerhart and Kirschner aim to explain the origins of phenotypic variation and evolutionary adaptation from within eukaryotic cell biological and developmental processes. Their examples are drawn from paleontology, developmental and cell biology.

Although evolutionary developmental biology is a new field, its origins lie in the last century; the search for connections between embryonic development (ontogeny) and evolutionary change (phylogeny) has been a long one. Evolutionary developmental biology is however more than just a fusion of the fields of developmental and evolutionary biology. It forges a unification of genomic, developmental, organismal, population and natural selection approaches to evolutionary change. It is concerned with how developmental processes evolve; how evolution produces novel structures, functions and behaviours; and how development, evolution and ecology are integrated to bring about and stabilize evolutionary change. The previous edition of this title, published in 1992, defined the terms and laid out the field for evolutionary developmental biology. This field is now one of the most active and fast growing within biology and this is reflected in this second edition, which is more than twice the length of the original and brought completely up to date. There are new chapters on major transitions in animal evolution, expanded coverage of comparative embryonic development and the inclusion of recent advances in genetics and molecular biology. The book is divided into eight parts which: place evolutionary developmental biology in the historical context of the search for relationships between development and evolution; detail the historical background leading to evolutionary embryology; explore embryos in development and embryos in evolution; discuss the relationship between embryos, evolution, environment and ecology; discuss the dilemma for homology of the fact that development evolves; deal with the importance of understanding how embryos measure time and place both through development and evolutionarily through heterochrony and heterotrophy; and set out the principles and processes that underlie evolutionary developmental biology. With over one hundred illustrations and photographs, extensive cross-referencing between chapters and boxes for ancillary material, this latest edition will be of immense interest to graduate and advanced undergraduate students in cell, developmental and molecular biology, and in zoology, evolution, ecology and entomology; in fact anyone with an interest in this new and increasingly important and interdisciplinary field which unifies biology.

The greatest mystery of life is how a single fertilized egg develops into a fully functioning, sometimes conscious multicellular organism. Embryogenesis Explained offers a new theory of how embryos build themselves, and combines simple physics with the most recent biochemical and genetic breakthroughs, based on the authors' prediction and then discovery of differentiation waves. They explain their ideas in a form accessible to the lay person and a broad spectrum of scientists and engineers. The diverse subjects of development, genetics and evolution, and their physics, are brought together to explain this major, previously unanswered scientific question of our time. As a follow up on The Hierarchical Genome, this book is a shorter but conceptually expanded work for the reader who is interested in science. It is useful as a starting point for the curious layman or the scientist or professional encountering the problem of embryogenesis without the formal biology background. There is also material useful for the seasoned biologist caught up in the new rush of information about the role of mechanics in developmental biology and cellular level mechanics in medicine.

A presentation of all aspects of neural crest cell origins (embryological and evolutionary) development and evolution; neural crest cell behavior (migration) and anomalies (neurocristopathies and birth defects) that arise from defective neural crest development. The treatment of development will include discussions of cellular, molecular and genetic aspects of the differentiation and morphogenesis of neural crest cells and structures derived from neural crest cells. The origins of the neural crest in embryology will be discussed using the recent information on the molecular basis of the specification of the neural crest. Also presented are the advances in our understanding of the evolution of jaws from studies on lampreys and of the neural crest from studies on ascidians and amphioxus.

Too tiny to see with the naked eye, the human embryo was just a hypothesis until the microscope made observation of embryonic development possible. This changed forever our view of the minuscule cluster of cells that looms large in questions about the meaning of life. Embryos under the Microscope examines how our scientific understanding of the embryo has evolved from the earliest speculations of natural philosophers to today’s biological engineering, with its many prospects for life-enhancing therapies. Jane Maienschein shows that research on embryos has always revealed possibilities that appear promising to some but deeply frightening to others, and she makes a persuasive case that public understanding must be informed by up-to-date scientific findings. Direct observation of embryos greatly expanded knowledge but also led to disagreements over what investigators were seeing. Biologists confirmed that embryos are living organisms undergoing rapid change and are not in any sense functioning persons. They do not feel pain or have any capacity to think until very late stages of fetal development. New information about DNA led to discoveries about embryonic regulation of genetic inheritance, as well as evolutionary relationships among species. Scientists have learned how to manipulate embryos in the lab, taking them apart, reconstructing them, and even synthesizing—practically from scratch—cells, body parts, and maybe someday entire embryos. Showing how we have learned what we now know about the biology of embryos, Maienschein changes our view of what it means to be alive.

During the past ten years, there has been a revolution in our understanding of developmental biology, as scientists apply the ideas and techniques of genetics and embryology to the processes of development. In this book, John Maynard Smith gives an account of the progress that has been made in this field -- in our knowledge of both the development of individuals and the evolution of the species. Maynard Smith points out that there is a parallel between the developmental changes that convert an egg into an adult and the evolutionary changes converted simple single-celled ancestors into the existing array of multicellular animals and plants. Genetic studies provide the necessary link between development and evolution: natural selection explains how information is incorporated in the genome, and development shows what use is made of it during the development of each individual. Traditionally, two very different views have been held about development. Maynard Smith argues that the differences between them are not so much scientific as ideological -- one can be considered reductionist and the other holistic. But because of advances in the science underpinning both viewpoints, he says, the possibility of a dialogue between them is great, which will be beneficial to the entire discipline.