Co-publication with Yale University Press (USA). Discussion of the biological diversity of the earth. Demonstrates how the natural systems that surround us play an essential role in protecting our basic life-support systems. Describes the millions of species providing ecosystem services and explains how biological diversity opens the way for new medicines, construction materials and designs, and manufactured goods. Urges us to protect the biological wealth of the earth from destructive human activity. Includes reccommended reading and index. Beattie is director of the Commonwealth Key Centre for Biodiversity and Bioresources at Macquarie University. Turnbull is a research associate at Macquarie. Erlich is Bing Professor of Population Studies at Stanford University.