Back from the brink: How 'frozen zoos' could save dying species

When Kurt Benirschke started collecting skin samples from rare and endangered animals in 1972, he didn't have a firm plan on what to do with them. As a researcher at the University of California San Diego, he believed that one day the tools would be developed to use them to save those animals. A few years later, he moved his collection to San Diego Zoo, and called it the Frozen Zoo.