Though biogeography may be simply defined--the study of the geographic distributions of organisms--the subject itself is extraordinarily complex, involving a range of scientific disciplines and a bewildering diversity of approaches. For convenience, biogeographers have recognized two research traditions: ecological biogeography and historical biogeography. This book makes sense of the profound revolution that historical biogeography has undergone in the last two decades, and of the resulting confusion over its foundations, basic concepts, methods, and relationships to other disciplines of comparative biology. Using case studies, the authors explain and illustrate the fundamentals and the most frequently used methods of this discipline. They show the reader how to tell when a historical biogeographic approach is called for, how to decide what kind of data to collect, how to choose the best method for the problem at hand, how to perform the necessary calculations, how to choose and apply a computer program, and how to interpret results.

Research whilst compiling this book has uncovered a fauna about twice the size as that previously published in the literature and consequently Systema Porifera revises and stabilizes the systematics of the phylum to accommodate this new knowledge in a contemporary framework. Practical tools (key illustrations, descriptions of character) are provided to facilitate the assignment of approximately 680 extant and 100 fossil genera. Systema Porifera is unique making sponge taxonomy widely available at the practical level of classification (genera, families, order). It is a taxonomic revision of sponges and spongiomorphis (such as sphinctozoans and archaeocyathans) based on re-evaluation of type materials and evidence. It is also a practical guide to sponge identification providing descriptions and illustrations of characters and interpretation of their importance to systematics. Systema Porifera addresses many long standing nomenclatural problems and provides a sound baseline for future debate on sponges and their place in time and space. Systema Porifera describes 3 classes, 7 subclasses, 24 orders, 127 families and 682 valid genera of extant sponges (with over 1600 nominal generic names and an additional 500 invalid names treated). Treatment of the fossil fauna is less comprehensive or critical, although 6 classes, 30 orders, 245 families and 998 fossil genera are mentioned. Keys to all recent and many fossil taxa are provided.

The sponge has attracted attention as one of the first animals to evolve multicellular organization. The sponge also interests scientists because it provides excellent research material in molecular phylogeny, allowing the process of animal diversification to be probed at the molecular level. Additionally, researchers have discovered in sponges certain bioactive substances with unique antibacterial and anticancer properties of great interest in medical and pharmaceutical science. Sponge Sciences presents the most up-to-date information on all areas of sponge research, with emphasis on taxonomy, molecular evolution, developmental biology, and natural products chemistry, as well as the biology of freshwater sponges. It also provides new findings in the morphology, cell biology, physiology, ecology, and biogeography of sponges. The papers compiled here are contributed by world-renowned sponge scientists.