Rise of the Necrofauna The Science, Ethics, and Risks of De-Extinction

There has been no shortage in recent years on books written for a general audience that talk about de-extinction: the controversial idea of resurrecting extinct species using recent advances in biotechnology. Futurist Alex Steffen catchily refers to them as the necrofauna mentioned in the book's title. Rather than focusing on the technical side of things, radio broadcaster and writer Britt Wray here foremost discusses the ethical, legal and other questions this idea raises. And once you start thinking about it in earnest, it raises many thorny issues. No wonder it has been a controversial issue.

The idea of bringing back species from the dead is one that disproportionately speaks to the public imagination, and if you've seen Jurassic Park, it's easy to see why. Wray is quick to put things into proper perspective though.

First off, for all the attention it has received, it's still only a fringe discipline, with only a handful of research groups working on it. Most of them have flocked to the banner of the non-profit organisation Revive & Restore.

Second, despite rapid developments in biotechnology there are still many technological hurdles. Wray walks the reader through the different techniques by which de-extinction might be achieved in the first chapter, making clear it is not as straightforward as Jurassic Park depicted it. Museum specimens of recently extinct species can offer you reasonably useful DNA fragments. But the DNA in mammoth carcasses pulled from the ice in Siberia is so degraded that it's hard to restore a full genome from it.

This brings us straight to the third sobering point Wray has to make. Can you really bring back an extinct species? If you want to be a pedant, no. Whether we would achieve this through backbreeding, cloning, or gene-editing closely related species, the best we can achieve is a so-called facsimile, a species that is genetically very similar to, say, a mammoth. But since we can't work with original DNA, the aim is to make something that is close enough. Furthermore we no longer have mammoth wombs in which to incubate our newly created embryos, so you need to resort to using surrogate mothers of a closely related species. And then there is the rearing of the newborn hybrid mammoth, we have no mammoth mothers either. Can an elephant mother properly raise a mammoth calf? All this affects the authenticity of the creature you are creating – it is clearly more than the sum of its DNA.

Wray has interviewed a host of people for this book, both opponents and proponents, to answer questions that go beyond these technical aspects though, and she does an excellent job to explore this contentious topic in all its facets in all the other chapters.

Some proponents argue that we have a moral duty to undo the damage we have done by driving certain species to extinction. Or that certain species performed important ecosystem functions that have since been lost. A group of Russian scientists in Siberia suggests that mammoths traipsing around the Siberian tundra were keeping the permafrost frozen by punching holes in the insulating blanket of snow, exposing the permafrost to cold Arctic air. It is true that the threat of permafrost thawing, releasing large amounts of methane in the process, is very serious. For the next few millenia at least it would send global temperatures soaring in a positive feedback loop. But resurrecting mammoths seems like an outlandish solution.

Which bring us to the opponents and their arguments. Conservation biologists point out that resurrected species might have no suitable environment left to return to. After they went extinct the world has not stopped turning. The idea that a gaping hole remains in an ecosystem when a species goes extinct is misleading. That's not how evolution works: species quickly move in to fill up the vacant niches that have become available, possibly forming new species in the process. There is the risk of resurrected species competing with existing species, possibly already threatened for other reasons. Not to mention that we need to understand why a species went extinct: Pollution? Overhunting? Will we have measures in place to stop it from happening again? Conservationists rightly point out that the resurrection movement should pay close attention to the lessons learned from species translocations: the reintroduction of a locally extinct species by moving animals back to their former habitats, which is a current strategy in conservation biology. Conflict with humans, damage caused by reintroduced wildlife, revenge killings when livestock is killed – if you have followed the news around reintroduction projects with wolves or lynx, this will sound familiar. All these things apply to resurrected species as well.

There are ethical implications too. Will we end up siphoning money away from current conservation efforts? And will the idea that we can always bring species back from extinction undermine current conservation efforts? How can we guarantee the welfare of the creatures we bring back? Is it morally defensible to exhibit them in a zoo or outdoor park, monetising them in the process? Or to hunt them (remember how the passenger pigeon went extinct...)? Not to mention the moral quandary of having to eradicate a newly resurrected species when things get out of hand and it turns into an invasive species. Environmental lawyers point out that current laws are completely not prepared to deal with this, and most legislative bodies have more pressing issues to draft rules for. If ever there was an idea where you think "We can, but *should* we?", this is it.

De-extinction raises many hairy questions that Wray explores in this book. Conservation biologist Paul Ehrlich has called it a "fascinating but dumb idea", and though I am normally quite open-minded about science stirring up controversy, I tend to agree with him. Luckily, Rise of the Necrofauna is not out to sell you on this idea. Wray is herself quite apprehensive about it, as she makes clear throughout. Some of the people she interviewed, notably conservation biologist Stuart Pimm, actually scolded her for writing this book. I wouldn't go that far. I do think the idea is fascinating, and I agree with Wray that the ongoing research could yield new insights (e.g. on ancient DNA) which is valuable for its own sake, and some of which can be applied to current conservation efforts. Luckily, some researchers involved underscore that that is a more important motivator than straight up de-extinction.

I have yet to read the other popular books on this topic, but even so, I can recommend Rise of the Necrofauna. Controversial as this topic is, Wray has written a fascinating book that reads effortlessly, is right up-to-date, and will surely fuel discussion.