When Kurt Benirschke, a researcher at the University of California San Diego, started collecting skin samples from rare and endangered animals in 1972, he didn't have a firm plan on what to do with them. A few years later, he moved his collection to San Diego Zoo, and called it the Frozen Zoo.
Benirschke passed away in 2018, but his efforts are very much alive. Today, the Frozen Zoo is the world's largest animal cryobank (冷库), with samples from over 10,500 individual animals from 1,220 species. It has reached some milestones in the field of genetics (遗传学), starting with the cloning of the first animal — a sheep named Dolly — in 1996.
Although cloning isn't perfect — an Indian ox they cloned only survived for 48 hours, it's a useful tool to help save endangered species, because it can increase genetic diversity. When the population of a species declines, the remaining animals are forced to reproduce within a closely related group, and thus the genetic pool becomes smaller, which further threatens survival. In a species of animals, the genetic diversity is what gives it flexibility, the ability to bounce back from big natural disasters, virus attacks or disease attacks. That's because if there are more different types of genetics in a species, there is a higher chance that some will survive.
With the current alarming rate of biodiversity loss, all researchers agree that a tighter cooperation between all cryobanks is a necessity. The task is enormous, because there are a million species at risk. "We need 50 different genetic samples from each, so that means 50 million samples; for each of those, we need five bottles for each sample, so that's hundreds of millions of samples that need to be stored," Ryder says.
"If we had a conversation with the future, they would say, please save as much biodiversity as you can, now. Period," he adds. "And they would say, do that by all means available."
