Several years ago, we realized that the most prominent ideas that had been ex pressed about the origin and early evolution of the Metazoa seemed to have been developed chiefly by zoologists using evidence from modern species without reference to the fossil record. Paleontologists had, in fact, put forth their own ideas but the zoological and the paleontological evidence were about the problem, seldom considered together, especially by zoologists. We believed that the paleon tological documentation of the first Metazoa was too scattered, too obscure to Western readers, and much of it too recent to have been readily available to our colleagues in zoology. Whether or not that was entirely true, we thought that a single volume reviewing the fossil record of the earliest Metazoa would be useful to many in both paleontology and zoology, especially since so much new informa tion has been developed in the last few years. Some of this information has been summarized in general articles recently, but an overview of most of the field does not exist. We therefore organized this book in five parts so that the evidence could be placed in perspective and summarized and inferences made from it. Part I intro duces the previous hypotheses that have been proposed for the origin and early radiation of Metazoa. Part II consists of two summary chapters that set the sedi mentological, geochemical, and biological background to the known radiations of Metazoa.
Providing an international perspective on the subject (including a summary of Russian and Chinese literature in English), contributions discuss previously proposed and new hypotheses for the origin and early radiation of Metazoa; give a sedimentological, geochemical, and biological description of th
Zoology, Volume 16: The Evolution of the Metozoa presents the significant results of the Cnidaria research, their interpretations and implications in the field of zoology. This book is composed of four chapters, and begins with the establishment of the systematic position of the Spongiae, the position of Ctenophora in the animal classification, and Cnidaria as the only Coelenterata. The subsequent chapter deals with a critical survey of the interpretations of the origin and nature of Cnidaria, with emphasis on the morphologic proofs of its phylogeny. These topics are followed by an outline of the most probable reconstruction of the phylogeny of Cnidaria and the descriptions of the evolution of this metozoa. The final chapter considers the established classification of the animal world and the genealogical tree. This book will be of value to zoologists and researchers who are interested in evolution and classification of Cnidaria.
This volume concentrates on the origin of multicellular animals, Metazoa. Until now, no unequivocal phylogeny has been produced. Therefore, the questions remain: Did Metazoa evolve from the Protozoa only once, or several times? Is the origin of animals monophyletic or polyphyletic? Especially the relationships between the existing lower metazoan phyla, particularly the Porifera (sponges) are uncertain. Based on sequence data of genes typical for multicellularity it is demonstrated that all Metazoa, including Porifera, should be placed into the kingdom Animalia together with the Eumetazoa. Therefore it is most likely that all animals are of monophyletic origin.
Larvae represent one of the classic problems of evolutionary biology and may explain how new body plans originate. It has often been suggested that many entirely unique body plans first originated as retained larvae of ancestral organisms. This book covers larval evolution and the developmental and evolutionary forces which shape and constrain them. Intended to contribute to a continuing dialectic, this book represents diverse opinions as well as manifold conclusions from an international team of leading zoologists and developmental biologists. Certain to challenge and intrigue, this book should be a part of the library of every evolutionary and developmental biologist interested in larvae and their significance. Key Features * Examines how vertebrate and invertebrate larvae develop and evolve * Presents four themes: development, evolution, metamorphosis, and genetic mechanisms * Chapters are organized into three sections: larval types and larval evolution, mechanisms of larval development and evolution, and larval functional morphology, physiology, and ecology
The growing success of molecular methods has challenged traditional views of animal evolution and a large number of alternative hypotheses are hotly debated today. For the deep metazoan phylogeny project, data sets of hitherto unmatched quality and quantity were compiled and analysed with innovative bioinformatics tools. The book begins at the base of the tree of life to discuss the origin of animals and early branches of the phylogenetic tree. The following section presents special data sets gained from mitochondrial genomes and from morphology, with a focus on nervous systems. The final section is dedicated to theoretical aspects of data analysis and new bioinformatics tools. The book closes with a unique general discussion of all hypotheses contained in previous chapters. This work provides the most comprehensive overview available of the state of the art in this exciting field of evolutionary research.
This book is divided in two parts, the first of which shows how, beyond paleontology and systematics, macroevolutionary theories apply key insights from ecology and biogeography, developmental biology, biophysics, molecular phylogenetics and even the sociocultural sciences to explain evolution in deep time. In the second part, the phenomenon of macroevolution is examined with the help of real life-history case studies on the evolution of eukaryotic sex, the formation of anatomical form and body-plans, extinction and speciation events of marine invertebrates, hominin evolution and species conservation ethics. The book brings together leading experts, who explain pivotal concepts such as Punctuated Equilibria, Stasis, Developmental Constraints, Adaptive Radiations, Habitat Tracking, Turnovers, (Mass) Extinctions, Species Sorting, Major Transitions, Trends and Hierarchies – key premises that allow macroevolutionary epistemic frameworks to transcend microevolutionary theories that focus on genetic variation, selection, migration and fitness. Along the way, the contributing authors review ongoing debates and current scientific challenges; detail new and fascinating scientific tools and techniques that allow us to cross the classic borders between disciplines; demonstrate how their theories make it possible to extend the Modern Synthesis; present guidelines on how the macroevolutionary field could be further developed; and provide a rich view of just how it was that life evolved across time and space. In short, this book is a must-read for active scholars and because the technical aspects are fully explained, it is also accessible for non-specialists. Understanding evolution requires a solid grasp of above-population phenomena. Species are real biological individuals and abiotic factors impact the future course of evolution. Beyond observation, when the explanation of macroevolution is the goal, we need both evidence and theory that enable us to explain and interpret how life evolves at the grand scale.
A collection of original essays by major thinkers, addressing how the biological sciences inform and inspire philosophical research.
This book reviews current topics on plant metabolism of air pollutants and elevated CO2, responses of whole plants and plant ecosystems, genetics and molecular biology for functioning improvement, experimental ecosystems and climate change research, global carbon-cycle monitoring in plant ecosystems, and other important issues. The authors, conducting research in Europe, the United States, Australia, and East Asia, present a wealth of information on their work in the field.
The Boron '97 meeting was a great success in summarising all recent developments in basic and applied research on boron's function, especially in plants. New techniques have since been developed and new insight has been gained into the role of boron in plant and animal metabolism. Nevertheless, there were still lots of open questions. The aim of the present workshop held in Bonn as a satellite meeting to the International Plant Nutrition Colloquium was thus to gather all actual information which has been gained since the Boron '97 meeting and to compile knowledge, both from animal and plant sciences. Furthermore, applied aspects had to be addressed too, as there is an increasing awareness of boron deficiencies even in crops such as wheat, which have formerly not been considered as responsive to boron application. Genetic differences in boron demand and efficiency within one species are a further important topic which has gained importance since the 1997 meeting. More in-depth knowledge on the mechanisms of boron efficiency are required as an increased efficiency will be one major possibility to maintain and improve crop yields for resource-poor farmers. Nevertheless, it has also clearly been shown that an adequate supply of boron is needed to obtain high yields of crops with a high quality, and that a sustainable agriculture has to provide an adequate boron supply to compensate for inevitable losses through leaching (especially in the humid tropics and temperate regions) and for the boron removal by the crop.
Inorganic polyphosphates - polymers of orthophosphate linked by high-energy phosphoanhydride bonds - have been found in apparently all forms of life, from bacteria, yeasts and fungi to higher plants and animals. These polymers, which had been neglected for a long time, have become a fascinating area of research in the last few years. This volume summarizes the present state of knowledge about the metabolism and function of inorganic polyphosphates. In addition, the methods to study these polymers as well as the biotechnological applications of inorganic polyphosphates are described. The 15 chapters of this volume, dealing with different aspects of polyphosphate research, are written by experts in the field. This book represents a valuable source of information not only for researchers working on this subject, but also for scientists interested in fundamental aspects of cell and energy metabolism.
In his 1894 book, Materials for the Study of Variation, William Bateson coined the term Homoeosis with the following prose: The case of the modification of the antenna of an insect into a foot, of the eye of a Crustacean into an antenna, of a petal into a stamen, and the like, are examples of the same kind. It is desirable and indeed necessary that such Variations, which consist in the assumption by one member of a Meristic series, of the form or characters proper to other members of the series, should be recognized as constituting a distinct group of phenomena. ...I therefore propose...the term HOMOEOSIS...; for the essential phenomenon is not that there has merely been a change, but that something has been changed into the likeness of something else. The book was intended as a listing of the kinds of naturally occurring variation that could act as a substrate for the evolutionary process and Bateson took his examples from collections, both private and in museums, of materials displaying morphological oddities. Interestingly the person who also coined the term “Genetics” proffered little in the way of speculation on the possible genetic underpinnings of these oddities. It wasn’t until the early part of the next century that these changes in meristic series were shown to be heritable.
The authors explore the late Precambrian and earliest Cambrian fossil record to explain the Cambrian phenomenon and discuss the possibility of a major turnover in marine ecology at the beginning of the Cambrian period or whether a new, improved type of animal appeared at this time. They support their often controversial conclusions with photos and illustrations of fossils, some never before published.
This 1985 book examines the origin of the present diversity of marine invertebrate animals. A brief review of the early stages in the history of life discusses the time-scale of the relevant geological periods alongside corresponding events in the evolutionary sequence. These views of the early history of life are then matched against the fossil record and conjectures drawn from the living fauna, enabling the author to attempt an overview of the early diversification of marine animal life. Transitions to the succeeding assemblages of shellbearing fossils in Palaeozoic rocks are discussed and a number of stratigraphic adjustments are suggested for the period in which evolutionary events had their greatest impact on oceans and marine rock strata. The need for an interdisciplinary approach to early evolution is emphasized.
Chemical Evolution of the Early Precambrian is a collection of papers presented at the Second College Park Colloquium on Chemical Evolution, held at the University of Maryland in October 1975. The book presents the discussions on the processes that led to the beginning of life on earth based on information gathered from the study of the Early Precambrian period. Topics on the origin of the atmosphere; early Precambrian weathering and sedimentation; carbon contents of early Precambrian rocks; and the establishment of the earliest date in the Precambrian period at which unambiguous living forms existed are expounded in the text. Geologists, biologists, chemists, paleobiologists, and students will find the book insightful and interesting.
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.
Animal phylogeny is undergoing a major revolution due to the availability of an ever increasing amount of molecular data, the application of novel methods of phylogenetic reconstruction, and advances in palaeontology and molecular developmental biology.This book revises the major events in animal evolution in the light of these recent advances.