Though I prefer seeing animals in the wild, I confess to being intrigued by zoos. I'm certainly not alone in my interest, as the long and varied history of zoological institutions shows.
The first recorded instance of a zoo -- or, at least, a private collection of animals -- dates from the Ancient Egyptian period. As public attractions, zoos first became popular in a big way in the 19th century. By the 1990s, 120 million visits were being made to them each year in the United States alone -- more than to all professional major sports games. And although visitor numbers have stagnated in recent years (according to some sources, attendance figures at Japan's zoos have halved since the late 1980s) zoos are still big business.
But moneymaking aside, what are zoos actually for?