Recently, evidence has been accumulated which shows that some of the groups formerly regarded as independent "phyla" such as Pogonophora (now recognized as Siboglinidae), Echiura, Myzostomida and perhaps Sipuncula, are most probably nothing else than greatly modified Annelida. The extreme morphological diversity found especially in Polychaeta displays the plasticity of a simple segmented organisation that basically is nothing else but a serial repetition of identical units. Thus, annelids are highly important to our understanding of fundamental questions about morphological and adaptive diversity, as well as clarifying evolutionary changes and phylogenetic relationships. The book aims to summarize our knowledge on Polychaetes polychaetes and their allies and gives an overview of recent advances gained by studies that employed conventional and modern methods plus, increasingly and importantly, the use of molecular markers and computer-assisted kinship analyses. It also reflects the state of art in polychaete sciences and presents new questions and controversies. As such it will significantly influence the direction of research on Polychaeta and their related taxa.

Systematics has developed rapidly during the past two decades. A multitude of new methods and contributions from a diversity of biological fields including molecular genetics and developmental biology have provided a wealth of phylogenetic hypotheses, some confirming traditional views others contradicting them. Despite such inconsistencies, it is now possible to recognize robust regions of a 'tree of life' and also to identify problematic areas which have yet to be resolved. This is the first book to apply the current state of phylogeny to an evolutionary interpretation of animal organ systems and body architecture, providing alternative theories in those cases of continuing controversy. Organs do not appear suddenly during evolution; instead they are composed of far simpler structures. In some cases it is even possible to trace particular molecules or physiological pathways as far back as pre-animal history. What emerges is a fascinating picture, showing how animals have combined ancestral and new elements in novel ways to form constantly changing responses to environmental requirements. The Evolution of Organ Systems starts with a general overview of current animal phylogeny, followed by review of general body organization including symmetry, anteroposterior axis, dorsoventral axis, germ layers, segmentation, and skeletons. Subsequent chapters then provide a detailed description of the individual organ systems themselves - integument, musculature, nervous system, sensory organs, body cavities, excretory system, circulatory system, respiratory system, intestinal system, gonads and gametes. Generously illustrated throughout, this accessible text is suitable for both upper level undergraduate and graduate students taking courses in animal evolution, organogenesis, animal anatomy, zoology and systematics. It will also be a valuable reference tool for those professional researchers in these fields requiring an authoritative, balanced and up-to-date overview of the topic.

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.

The nervous system is particularly fascinating for many biologists because it controls animal characteristics such as movement, behavior, and coordinated thinking. Invertebrate neurobiology has traditionally been studied in specific model organisms, whilst knowledge of the broad diversity of nervous system architecture and its evolution among metazoan animals has received less attention. This is the first major reference work in the field for 50 years, bringing together many leading evolutionary neurobiologists to review the most recent research on the structure of invertebrate nervous systems and provide a comprehensive and authoritative overview for a new generation of researchers. Presented in full colour throughout, Structure and Evolution of Invertebrate Nervous Systems synthesizes and illustrates the numerous new findings that have been made possible with light and electron microscopy. These include the recent introduction of new molecular and optical techniques such as immunohistochemical staining of neuron-specific antigens and fluorescence in-situ-hybridization, combined with visualization by confocal laser scanning microscopy. New approaches to analysing the structure of the nervous system are also included such as micro-computational tomography, cryo-soft X-ray tomography, and various 3-D visualization techniques. The book follows a systematic and phylogenetic structure, covering a broad range of taxa, interspersed with chapters focusing on selected topics in nervous system functioning which are presented as research highlights and perspectives. This comprehensive reference work will be an essential companion for graduate students and researchers alike in the fields of metazoan neurobiology, morphology, zoology, phylogeny and evolution.

Generally, biologists and mathematicians who study the shape and form of organisms have largely been working in isolation from those who work on evolutionary relationships through the analysis of common characteristics. Increasingly however, dialogue between the two communities is beginning to develop - but other than a handful of journal papers, t

This book is the second volume in a series of 4 volumes in the Handbook of Zoology series treating morphology, anatomy, reproduction, development, ecology, phylogeny, systematics and taxonomy of polychaetous Annelida. In this volume a comprehensive review of a few more derived higher taxa within Sedentaria are given, namely Sabellida, Opheliida/Capitellida as well as Hrabeiellidae. The former comprise annelids possessing a body divided into two more or less distinct regions or tagmata called thorax and abdomen. Here two groups of families are united, the spioniform and sabelliform polychaetes. Especially Spionidae and Sabellidae are speciose families within this group and represent two of the largest annelid families. These animals live in various types of burrows or tubes and all possess so-called feeding palps. In one group these appendages are differentiated as grooved feeding palps, whereas in the other they may form highly elaborated circular tentacular crowns comprising a number of radioles mostly giving off numerous filamentous pinnulae. Often additionally colourful, the latter are also received the common names "feather-duster worms", "flowers of the sea", "Christmas-tree worms". Opheliida/Capitellida including five families of truly worm-like annelids without appendages represents the contrary. Their members burrow in soft bottom substrates and may be classified as non-selective deposit feeders. Molecular phylogenetic analyses have shown that Echiura or spoon worms, formerly regarded to represent a separate phylum, are members of this group. Last not least Hrabeiellidae is one out of only two families of oligochaete-like terrestrial polychaetes and for this reason received strong scientific interest.