Endangered black-and-white lemurs in captive breeding programs can now be bred without the chest deformity that was responsible for the deaths of countless newborns thanks to the Frozen Zoo. The Frozen Zoo’s extensive inventory of ova, semen, and skin samples from endangered species enables scientists to research birth defects, and to artificially inseminate threatened animals.

Many proponents of captive breeding programs argue that managed propagation such as that done with the help of the Frozen Zoo is the only way to save a depleted species from extinction. Jared Diamond, professor of physiology at the University of Cambridge, argues that “there are already many species that survive only because self-sustaining captive populations were established before the animals became extinct in the wild.” While proponents of captive breeding generally advocate the release of the offspring to the wild...