The arthropods contain more species than any other animal group, but the evolutionary pathways which led to their current diversity are still an issue of controversy. Arthropod Relationships provides an overview of our current understanding, responding to the new data arising from sequencing DNA, the discovery of new Cambrian fossils as direct evidence of early arthropod history, and developmental genetics. These new areas of research have stimulated a reconsideration of classical morphology and embryology. Arthropod Relationships is the first synthesis of the current debate to emerge: not since the volume edited by Gupta was published in 1979 has the arthropod phylogeny debate been, considered in this depth and breadth. Leaders in the various branches of arthropod biology have contributed to this volume. Chapters focus progressively from the general issues to the specific problems involving particular groups, and thence to a consideration of embryology and genetics. This wide range of disciplines is drawn on to approach an understanding of arthropod relationships, and to provide the most timely account of arthropod phylogeny. This book should be read by evolutionary biologists, palaeontologists, developmental geneticists and invertebrate zoologists. It will have a special interest for post-graduate students working in these fields.