Stuart Pimm, Doris Duke chair of conservation ecology at the Nicholas School of the Environment, is a species extinction expert who discourages species revival or de-extinction. Pimm recently had an opinion piece published in National Geographic discussing the impracticalities of de-extinction and why conservation should take precedence. The Chronicle spoke with Pimm to discuss his viewpoints on de-extinction.

The Chronicle: What exactly is de-extinction?

Stuart Pimm: What people are trying to do is exactly what happens in [the movie] “Jurassic Park,” where a bunch of scientists bring back the dinosaurs. Now, nobody’s trying to bring back the dinosaurs, but nonetheless, they are trying to bring extinct species back by genetically engineering them. One of the notions is the passenger pigeon. You get some passenger pigeon DNA, and insert it into the nucleus of the embryo of a regular pigeon, and what you would get out of that is not a regular pigeon, but a passenger pigeon.

TC: Because passenger pigeons are extinct, what are the sources of their DNA?

SP: In much of the same way as the fossil DNA from the dinosaurs, which was a bit of a stretch, incidentally. Nevertheless, there are plenty of passenger pigeons in museums, very much dead, but you can resurrect the DNA.

TC: Why do proponents of de-extinction think it would be valuable to bring back extinct species?

SP: They think that it’s a way, and I certainly agree, of getting back species that we have driven to extinction with absolute carelessness. And I think it would be great to have a species that we’ve driven to extinction back, but unfortunately, it’s not anywhere near as simple as that.

TC: What sorts of challenges stand in the way of species revival?

SP: The problem is that reviving one species is always a very tiny part. The story in “Jurassic Park” is there’s a botanist who sees a tree that’s been extinct for a million years and is absolutely overwhelmed by this huge dinosaur, a sauropod, eating its leaves. The only problem with that is those big dinosaurs would need thousands of those trees, and you’d have to grow them too. You can’t just put one species back, you have to worry about a very large number of other species—plants, animals, insects, pollinators and symbiotic fungi. Recreating nature is a very complex task.

TC: Do you think that species revival is a waste of time?

SP: It’s not that I care that much about people wasting their time—their time, their money. But it is politically damaging. People were worried about how rapidly the old growth forests of the Pacific Northwest were being logged because of the spotted owl that lives there. At the rate they were going, they predicted that 90 percent of the spotted owls would be gone within 60 years. People said, “No, we have to stop logging, or we’ll drive the spotted owl to extinction.” The argument then was that “couldn’t we log a lot more forest, and if the spotted owl is driven to extinction in the wild, we can keep them going in captive breeding programs?” But the problem is it wasn’t just the spotted owl—there were 300 other species that lived in those forests. So there’s always a lot more at stake than just the species you’re worried about. So can we restore the old growth forests of the southeastern United States where the passenger pigeon lived? Not easily! We have massively changed the landscape in the southern states, so even if we had the passenger pigeon, where would we put it?

TC: Do you think that the intrinsic value of having an extinct species back is something worthwhile?

SP: Don’t get me wrong, driving species to extinction is a bad thing. Bringing that species back is a good thing. But, there are a lot of “buts.” That isn’t to say that people shouldn’t do it, but it makes politicians think that they can do enormous amounts of environmental harm and it’s all fine because we can bring a species back if we drive it to extinction. But the fact is that 99 percent of all species we drive to extinction we are not going to bring back, because they would not be as charismatic as the passenger pigeon.

TC: You mention that conservation should focus on tasks at hand, like protecting endangered species. If there is a necessary trade-off between humans and nature, which there often is, how should we determine what species deserve to be protected?

SP: I don’t concede that we should let any species go extinct. I think that it is a very bad thing. The fact that we are driving species to extinction 1,000 times faster than they would naturally is a measure of how irreversible and unsustainable our impacts upon the environment are. We should stop and say, “Hey, there are other ways of doing things. We don’t have to treat our environment with the contempt that we have been doing.”

TC: When you watch “Jurassic Park,” do these issues cross your mind as you watch or make the movie less fun to watch?

SP: Not at all, “Jurassic Park” is a wonderful fantasy and a beautiful movie to watch. I enjoyed it. But it is a fantasy and not a reality.