Collecting and displaying live animals, often from exotic locales and faraway continents, has been part of human life for at least 4,500 years. Originally featured in royal or imperial parks and pleasure gardens, upon the rise of bourgeois culture such animal collections opened to the public and became known as zoological gardens, or zoos, where visitors could contemplate "the wild" and its relationship to human civilization. By the end of the twentieth century a zoo visit had become one of the rituals of modern life, particularly during childhood; according to a study by the American Association of Zoological Parks and Aquariums, 98 percent of all American and Canadian adults had been to a zoo by 1987, and one-third of them had paid a visit in the last year. Around the same time, the legitimacy of collecting and displaying animals became hotly debated, with some people arguing that putting animals in any...