Researchers at the San Diego Zoo’s Institute for Conservation Research—home to a frosty menagerie known as the Frozen Zoo—are working to give northern white rhinos a second chance. Since 1975, the institute has been collecting tissues from creatures, some endangered and some not, then growing the cells in the lab and preserving them at a chilly 321 degrees below zero Fahrenheit.
Zoos already use reproductive technologies such as in vitro fertilization for animals like gorillas, and artificial insemination for pandas. The Frozen Zoo has used its preserved sperm to create pheasant chicks, for example, and has gone as far as making embryos of cheetahs and fertilizing the eggs of southern white rhinoceroses.
Humans have been doing that for a long time: We’ve caused species extinctions. We’ve irretrievably changed their habitats. We’ve altered their behavior. We’ve intermixed them. We’ve altered their environments, their predators, their diseases. All of these things we have already done.