Sydney's first new major zoo in more than 100 years will open on Saturday. With such debate about animal welfare these days, can zoos still be a force for good? Gary Nunn reports from Sydney. Zoos have evolved significantly since they were first created. Their original purpose was braggadocio: a way for the wealthy to display their power in private collections. Later, they helped with science research. Then they became tourist attractions the public would pay to view. It wasn't until the 1970s onwards that conservation emerged as a priority.