People have always been curious about the plants and animals with which they coexist. Primitive cultures identified edible and poisonous plants largely by trial and error, and then used them for hunting, executions, euthanasia, and magico-religious rites, as well as for their medicinal properties. In this fascinating book, John Mann investigates the evolution of modern medicine from its roots in folk medicine, and reveals the continuing importance of natural plant and animal products, many of which remain undiscovered but under threat by the wholesale destruction of the Earth's wild places. In this new edition, he has updated the material to include discussion of the background to some of the most talked about drugs of recent years, including Prozac and Viagra.