Humans are threatening the animal kingdom by taking over habitats, polluting our skies and waterways and fueling global warming, creating an extinction event not seen in more than 10 million years. There are more than 1 million species on the brink of disappearing right now. Thankfully, there are organizations working to save those species, and to collect the biological materials necessary to bring them back when the technology is ready to do so. Among those organizations is the San Diego Zoo Wildlife Alliance. Barbara Durrant, Director of Reproductive Sciences and Marlys Houck, curator of the Frozen Zoo share the important work they are doing with host Steve Fisher.