In my feature on de-extinction in the April issue of National Geographic, I tried to capture the debate in the scientific community about whether we should try to bring vanished species back to Earth. It’s been gratifying to see a spirited, sustained conversation going on ever since. The prospect of de-extinction raises important issues that have to be grappled with. Is it better to spend money trying to revive a mammoth or to secure a vast swath of rain forest? Are objections to de-extinction driven by a flawed notion of what’s natural? Would it make more sense to use the emerging tools of biotechnology to prevent endangered species from disappearing, rather than attempting to bring back the extinct ones?

But I’m frustrated by