If human beings had chosen a hundred years ago to stop using animals in scientific and medical research, the world would be a very different place today. Many of us are here because we did not die as children, or our parents did not die, from diseases that have been controlled through the knowledge gained from animal research. The biological information that has unlocked the secrets of genetics, shed light on the workings of the brain, and made it possible to understand new diseases like AIDS would not exist. Even the animals that we keep as pets and raise for food would live shorter and less healthy lives, because many of the vaccines and treatments that have become staples of veterinary medicine would never have been developed.