This is closely related to #3. Leakey and Lewin (1995) called the tropical rainforest a “cauldron of evolutionary innovation.” As species are eliminated or their genetic variability is lessened by population depletion, we lose the potential for producing new varieties of food, fiber, medicines and other crops. Genes cannot be manufactured; we need the genetic resources of current species to provide new and improved varieties. This is especially critical as the size of the human population continues to climb. Since much of the suitable agricultural land is already being utilized, providing sufficient food and other materials for our burgeoning population must come from the manipulation of genetic resources – “manufacturing” new crops and animals by selection, and by the development of transgenic organisms.