Tomatoes could not be grown commercially without the help of their wild relatives. A single wild species of rice has helped double rice production in Asia. Wild silk-worms are enabling India to expand its silk industry. A wild carp with resistance to cold has been used to extend Soviet carp production further into the north. Wild genetic resources - the heritable characteristics of wild plants and animals - are used increasingly to improve domesticated crops and livestock and as new sources of food and of raw materials. But habitat destruction, over-exploitation and competition from introduced species is destroying many gene pools even before they have been identified. describes the growing contribution of wild genetic resources to the production of food and raw materials, describes their characteristics, explains the benefits and problems of using them and outlines the ways in which they are threatened and the measures being taken to conserve them. Originally published in 1988