An increasingly popular field of study is the traditional knowledge of indigenous peoples. Recognizing that nearly two-thirds of the useful domestic food plants have their origin in the Western hemisphere, scholars, native and otherwise, have been investigating the possibility that non-Western peoples have a science of their own capable of making profound discoveries about the usefulness of the natural world. Drug companies scour the jungles of Central and South America in search of medicinal plants from which chemicals can be derived that will prove effective in the fight against disease. In short, the traditional knowledge of indigenous people is big business in both private and public spheres of inquiry.