What is extinction? What causes it? Can it be prevented? In The Great Extinctions leading palaeontologist Norman MacLeod reveals how, contrary to popular conception, species extinction is as natural a process as species evolution. Examining extinction over geological time, he compares ancient extinction events and uses them to predict what might happen in the future. Life's rich tapestry has escalated over time, despite several major setbacks. In total some 1,000 - 3,000 million species are estimated to have appeared during Earth's history, yet only 12.5 million currently exist today. This means that the overwhelming majority of species that have ever lived are extinct. Featuring the latest evidence on the subject and informative illustrations and diagrams throughout, The Great Extinctions is an absorbing guide to extinctions, their causes and their effects on evolutionary processes. As the debates about man's impact on the environment, about biodiversity and about conservation and extinction, continue, this book is essential reading for popular science enthusiasts and all those with an interest in natural history or environmental issues.