Kiwis and other native birds in New Zealand are in trouble. In the 19th century, European traders and immigrants introduced many foreign rats, stoats and other animals to the South Pacific island nation. Since then, many of these non-native animals — known as invasive species — have been preying on the native birds, some of which don’t fly. New Zealand’s leaders want to get rid of the invaders. And a new technology could help. But scientists are now questioning whether that is a smart thing to do.
Kevin Esvelt is an evolutionary ecologist at the Massachusetts Institute of Technology in Cambridge. An evolutionary ecologist studies the genetics of living things and how species have changed over time. “You need to be very careful,” Esvelt says. It’s always possible, he notes, that some “solution” might cause problems elsewhere in an ecosystem.
Esvelt is talking with people in New Zealand about a plan. They’re considering use of a type of gene-editing tool known as a gene drive. It can copy and paste itself into the genome of an organism. (A genome is the complete set of genetic instructions in an organism.) Once the gene drive is inside the genome, it could change the genes of some invasive species in a way that would make that species die off at sites where it doesn’t belong.
That may sound like a good thing. Indeed, many scientists hope it will be. Still, they have concerns. After all, if a gene drive “escapes,” it could kill that targeted species even in places where it does belong.
Tina Saey of Science News magazine has a doctorate degree in molecular genetics. She has covered gene editing and gene drives a lot. In an award-winning feature story in the magazine, she notes: “Researchers have designed ways to keep [gene drives] confined in the lab.” However, she adds, “no such safety nets exist for gene drives released into the wild.”
Wiping out an entire species, even if it’s a pest, raises questions about whether such a move would be the right thing to do. To date, she points out, scientists and policymakers are only just starting to think about this.