Different species of animals vary so enormously in their reactions to toxins and diseases and in their metabolism of drugs that studies with animals are not good indicators for people. For example, a dose of aspirin that is therapeutic in humans is poisonous to cats and has no effect on fever in horses; benzene causes leukemia in humans but not in mice; insulin produces birth defects in animals but not in humans, and so on. Today’s sophisticated “super” computers can actually predict the effect of substances on all the organs of the human body.
