What is the minimum viable population (MVP) of a particular species? Besides the obvious implications for conservation, especially of endangered species, this question raises important issues in population biology. MVP obviously varies with demographic, life history and environmental factors, but also depends upon genetic load and genetic variability. This book addresses the most recent research in the rapidly developing integration of conservation biology with population biology. Chapters consider the roles of demographic and environmental variability; the effects of latitude, body size, patchiness and metapopulation structure; the implications of catastrophes; and the relevance of effective population size on inbreeding and natural selection. Other topics addressed include the role of decision theory in clarifying management alternatives for endangered species, and the opportunities for improved co-operation between agencies responsible for management. The book concludes with a forward-looking and plain-speaking summary on future research and its application for conservation practice.