In a 2006 article in DVM360, Zoo animals and wildlife veterinarian, Dr. Eric Miller, explains how zoos play a bigger role than just entertainment. In fact, zoos are a key component in wildlife education, research and in the preservation of all zoo animals and wildlife that are threatened with extinction.

http://veterinarymedicine.dvm360.com/aaas-symposium-wildlife-captivity-ethics-and-zoos