Animal Cloning: The Next Phase

For a northern white rhinoceros, Angalifu has a pretty sweet life. The two-ton rhino can roam freely through a 213-acre habitat that resembles the African savannah. Still, Angalifu and his pal Nola, an elderly female at the zoo, are two of eight northern white rhinos believed to be left on the planet. "These beautiful animals are on the brink," says Oliver Ryder, the chief geneticist at the San Diego Zoo's Institute for Conservation Research. "There are a few left, but it's not clear they're capable of reproducing."

Ryder oversees the Frozen Zoo, a lab where skin cells and DNA from 12 white rhinos and 8,400 other animals—a total of some 800 species—are stored at -280F. The hope is that scientists can use the cells to create cloned animals and replenish endangered species.