– Olivier Rieppel, Rowe Family Curator of Evolutionary Biology, Negaunee Integrative Research Center, Field Museum, USA Species, or ‘the Species Problem’, is a topic in science, in the philosophy of science, and in general philosophy. In fact, it encompasses many aspects of the same problem, and these are dealt with in this volume. Species are often thought of as fundamental units of biological matter to be used in ecology, conservation, classification, and biodiversity. The chapters in this book present opposing views on the current philosophical and conceptual issues of the Species Problem in biology. Divided into four sections, , , and , the book is authored by biologists, philosophers, and historians, many leaders in their fields. Topics include ontology of species, definitions of both species category and units, species rank, speciation issues, nomenclature, ecology, and species conservation. Species Problems and Beyond aims to clarify the contemporary issues of the Species Problem. It is ideal for use in upper-level seminars and courses in Evolutionary Biology, Philosophy of Science, Philosophy of Biology, Systematics and Taxonomy, and Phylogenetics/Cladistics, and for any scholar in these fields.