Animal testing is when scientists, students or commercial firms such as cosmetic companies use animals for biological research, typically in a laboratory setting.
These experiments are aimed at judging the safety and effectiveness of drugs, vaccines and products; researching how the human body works or fights disease; and educational purposes.
Defenders of animal testing credit it for major medical breakthroughs, including penicillin, insulin, the polio vaccine, chemotherapy for childhood leukemia, hip replacement and heart bypass surgeries. They find the loss of animal life and well-being an acceptable price to pay for the benefits to humans.
Those against animal testing generally argue that it's cruel, unnecessary, scientifically unsound and expensive, and that the results are misleading. They believe that more accurate testing can be carried out with computer modeling, clinical trials, epidemiological studies, human tissue and cell cultures, autopsies and biopsies.
The idea that human life is not inherently more valuable than other forms of animal life was popularized by the 1975 book "Animal Liberation" by philosopher Peter Singer. Singer's book is credited with launching the modern animal rights movement.
Ninety percent of animal research is conducted on rodents and birds, but until the fall of 2000, neither was included under the 1966 Animal Welfare Act, which requires humane care of animals used in laboratories, placed on exhibition and kept as pets.
Approximately 1,600 chimpanzees are housed in U.S. research facilities, and the National Association for Biomedical Research estimates that nearly 23 million rats and mice "were used in experiments" in 1998. PETA's estimates are much higher.
