The current extinction crisis is of human making, and any favorable resolution of that biodiversity crisis--among the most dire in the 4-billion-year history of Earth--will have to be initiated by mankind. Little time remains for the public, corporations, and governments to awaken to the magnitude of what is at stake. This book aims to assist that critical educational mission, synthesizing recent scientific information and ideas about threats to biodiversity in the past, present, and projected future. This is the second volume from the In the Light of Evolution series, based on a series of Arthur M. Sackler colloquia, and designed to promote the evolutionary sciences. Each installment explores evolutionary perspectives on a particular biological topic that is scientifically intriguing but also has special relevance to contemporary societal issues or challenges. Individually and collectively, the ILE series aims to interpret phenomena in various areas of biology through the lens of evolution, address some of the most intellectually engaging as well as pragmatically important societal issues of our times, and foster a greater appreciation of evolutionary biology as a consolidating foundation for the life sciences.