The main purpose of the volume is to present an ecological perspective on biodiversity by examining its two facets, the ecological causes and consequences of biodiversity changes. The book extends its scope to cover the linkage between science and management issues, again from an ecological perspective. This volume commemorates the awarding of the 1993 International Prize for Biology to Professor Edward O. Wilson. He provides the introductory chapter for a new stage of biodiversity research, which Ed Wilson pioncered, and will serve as a suitable tributeto him.