Animal Cloning: The Next Phase  San Diego's Frozen Zoo stores
cells of endangered species such as the white rhino, but it's a
controversial procedure that hasn't yielded optimal results  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.  The lab was founded
in 1972, but technology needed t