Stephen M. Shuster

Published by Sinauer Associates, an imprint of Oxford University Press. In the twelve years since publication of Invertebrates, Second Edition, fundamental shifts have occurred in our understanding of the origins and evolutionary relationships among protists and animals. These changes are largely due to the explosion of molecular phylogenetics and evo-devo research, emergence of the new field of animal genomics, major fossil discoveries in China, Australia, and elsewhere, and important new embryological and ultrastructural studies. As a result: - New phyla have been described (e.g., Micrognathozoa, Xenacoelomorpha). - Old phyla have been collapsed into others (e.g., Sipuncula and Echiura are now placed within Annelida; acanthocephalans are now known to be highly modified, parasitic rotifers). - Phyla once thought to be deuterostomes are now part of the protostome clade (e.g., Chaetognatha, Phoronida, Bryozoa, Brachiopoda). - The Protostomia has been reorganized into two major clades known as Ecdysozoa and Spiralia. For each of the thirty-two currently recognized phyla, Invertebrates, Third Edition, presents detailed classifications, revised taxonomic synopses, updated information on general biology and anatomy, and current phylogenetic hypotheses, organized with boxes and tables, and illustrated with abundant line drawings and new color photos. The chapters are organized around the "new animal phylogeny," while introductory chapters provide basic background information on the general biology of invertebrates. Two new coauthors have been added to the writing team, and twenty-two additional invertebrate zoologists have contributed to chapter revisions. This benchmark volume on our modern views of invertebrate biology should be in every zoologist's library.

This book presents the first unified conceptual and statistical framework for understanding the evolution of reproductive strategies. Using the concept of the opportunity for sexual selection, the authors illustrate how and why sexual selection, though restricted to one sex and opposed in the other, is one of the strongest and fastest of all evolutionary forces. They offer a statistical framework for studying mating system evolution and apply it to patterns of alternative mating strategies. In doing so, they provide a method for quantifying how the strength of sexual selection is affected by the ecological and life history processes that influence females' spatial and temporal clustering and reproductive schedules. Directly challenging verbal evolutionary models that attempt to explain reproductive behavior without quantitative reference to evolutionary genetics, this book establishes a more solid theoretical foundation for the field. Among the weaknesses the authors find in the existing data is the apparent ubiquity of condition-dependent mating tactics. They identify factors likely to contribute to the evolution of alternative mating strategies--which they argue are more common than generally believed--and illustrate how to measure the strength of selection acting on them. Lastly, they offer predictions on the covariation of mating systems and strategies, consider the underlying developmental biology behind male polyphenism, and propose directions for future research. Informed by genetics, this is a comprehensive and rigorous new approach to explaining mating systems and strategies that will influence a wide swath of evolutionary biology.