After animal tests have proven the safety of new drugs, patients asked to participate in further studies can be assured that they may fare better, and will not do worse than if they were given standard treatment or no treatment. New surgical techniques first must be carefully developed and tested in living, breathing, whole organ systems with pulmonary and circulatory systems much like ours. The doctors who perform today's delicate cardiac, ear, eye, pulmonary and brain surgeries, as well as doctors in training, must develop the necessary skills before patients' lives are entrusted to their care. Neither computer models, cell cultures, nor artificial substances can simulate flesh, muscle, blood, and organs like the ones in live animals. There is no alternative to animal research.
Living systems are complex.
The nervous system, blood and brain chemistry, and gland secretions are all interrelated. It is impossible to explore, explain or predict the course of many diseases or the effects of many treatments without observing and testing the entire living system. But these are only isolated tests. And isolated tests will yield only isolated results, which may bear little relation to a whole living system. Scientists do not yet know enough about living systems or diseases, nor does the technology exist, to replicate one on a computer.