To be sure, there is a long way to go. The mice Colossal created include several genetic changes previously known to make mice furry or long-haired. That is, the changes were mammoth-like, but not from a mammoth. In fact, only a single letter of uniquely mammoth DNA was added to the mice.
Because this idea is so new and attracting so much attention, I decided it would be useful to create a record of previous attempts to add extinct DNA to living organisms. And since the technology doesn’t have a name, let’s give it one: “chronogenics.”
“Examples are exceptionally few currently,” says Ben Novak, lead scientist at Revive & Restore, an organization that applies genetic technology to conservation efforts. Novak helped me track down examples, and I also got ideas from Harvard geneticist George Church—who originally envisioned the mammoth project—as well as Beth Shapiro, lead scientist at Colossal.
The starting point for chronogenics appears to be in 2004. That year, US scientists reported they’d partly re-created the deadly 1918 influenza virus and used it to infect mice. After a long search, they had retrieved examples of the virus from a frozen body in Alaska, which had preserved the germ like a time capsule. Eventually, they were able to reconstruct the entire virus—all eight of its genes—and found it had lethal effects on rodents.
This was an alarming start to the idea of gene de-extinction. As we know from movies like The Thing, digging up frozen creatures from the ice is a bad idea. Many scientists felt that recovering the 1918 flu—which had killed 30 million people—created an unnecessary risk that the virus could slip loose, setting off a new outbreak.