The camera flies across a vast, barren, grassland. In the distance a group of woolly mammoths traipse across the landscape. As the camera gets closer we see the herd to be 30-40 strong, the giant tusks of the adults glinting in the low autumn sun. A calf runs playfully between their legs, its feet kicking up an early dusting of snow; trunk flailing wildly as if it still hasn’t quite learned how to control it.
This scene is one that hasn’t existed on earth in thousands of years, but it is one scientists are trying to recreate. This September the genetics company Colossal Biosciences announced that it has secured $15m in funding to create an elephant-mammoth hybrid with the aim of producing cold-resistant elephants that they say could help restore degraded habitats in the Arctic tundra, a vast area that once covered much of Eurasia.
You may notice that this description isn’t quite the same as the “bringing back the woolly mammoth” of news headlines. Colossal are using genetic engineering to create a new type of elephant that looks and maybe acts a bit like a woolly mammoth.
There are three pathways to resurrecting extinct species, and none of them will enable us to bring species already extinct “back from the dead”. Genetic engineering combines DNA from extinct species with that of living relatives to produce a hybrid that hopefully expresses more traits from the extinct species than the extant. Cloning, the only method that can truly bring back a genetic replica of an individual, requires living tissue, so is only useful for species that are going extinct, if we collect and store their tissue ahead of time. Back-breeding, the final pathway, uses selective breeding to pick out traits that match those of their ancient ancestors.
None of these methods can truly bring back species that are already extinct. The skies will never be filled again with giant flocks of passenger pigeons, the tundra will never echo with the call of woolly mammoths, and we will never have pet dodos. These animals are gone, we can and should mourn their loss, but we can never undo what has been done.
I could, and maybe should, leave things there. If we can’t actually bring species back from extinction, what more is to be said? But it seems that many people are perfectly happy at the thought of creating these facsimiles, coming up with all sorts of justifications for why we should. Do these justifications hold up to scrutiny? As someone with a background in ecology and an interest in evidence-based conservation, I don’t think they do.
These justifications can be summarised as necessity (there’s too much going extinct to save everything, this gives us a back-up plan); moral duty (we broke it, we fix it); ecological restoration (extinct species played a unique and vital role that cannot be recreated any other way); scientific and technological advances (even if it doesn’t work out we will learn a lot); and the “wow factor” (extinct animals are exciting and people want to see them). So let’s look at each of these in turn.
Necessity
The latest figures from the IUCN Red List show that we are in the midst of a biological catastrophe. Of the 2.1 million species so far described scientifically, only 7% have had their extinction risk assessed. But of those 138,374 species, over a quarter have been classified as “threatened” (either critically endangered, endangered, or vulnerable).
These figures may sound like a powerful argument for increasing our efforts in de-extinction, particularly with the potential that cloning brings to species that are already in their final generations. However, as Bennett and colleagues argued, diversion of limited resources to de-extinction efforts over those to protect threatened species could lead to a net species loss, even if those efforts were successful. Actively working on de-extinction projects feels akin to trying to relight your decorative candle while your house is on fire.
Moral Duty
This is, on the surface, a compelling argument, reminding us that we must face the consequences of our actions. But de-extinction feels like apologising without understanding what we’re apologising for.
While extinction is a natural and necessary process, the extinction crisis we are experiencing today is unique in Earth’s history. This modern crisis has been caused not by geological activity or an asteroid impact but by the actions of a single species. Those actions have led to extraordinary changes in the chemical composition of our atmosphere, to changes in the types and extents of habitats with many experiencing huge reductions, and in changes to species composition of communities through introductions of flora and fauna as they have been transported around the globe. Many species have also experienced targeted extermination, being viewed either as a pest or a food source, or sometimes both.
Until we are willing to make the necessary changes to prevent and reverse this degradation of our planet, all de-extinction does is provide us another opportunity to drive these species to extinction.
Ecological Restoration
Ecological restoration is the primary reason given for many de-extinction projects. Colossal explain:
…if the Mammoth Steppe ecosystem could be revived, it could help in reversing the rapid warming of the climate and more pressingly, protect the arctic’s permafrost – one of the world’s largest carbon reservoirs.
To achieve this level of ecological modification you need a lot of mammoths. A small herd in Pleistocene Park won’t be enough, and as Dr Tori Herridge explained in her excellent Twitter thread on the announcement, achieving sufficient numbers would take decades with no guarantee of having any significant impact on the ecosystem.
The problem that is often missing in these discussions is that the habitats have changed significantly since these species were last alive. Mammoths are a species that lived during the Ice Age. Our planet has changed significantly since that time and there’s no guarantee that, even if we could create a simulacra of them, they would play the same role in their environment as they did historically. Even more recently-extinct species such as passenger pigeons rely on resources that simply don’t exist any more due to intentional habitat destruction. No amount of passenger pigeons are going to convert farmland back to forest.
Scientific and Technological Advances
As Aaron Rabinowitz so deftly argued in a recent article for The Skeptic, progress and scientific advancement is not as simple as “things get better”. For all the visible benefits there are often many hidden costs, and in the case of de-extinction the opportunity costs are significant.
Colossal proposes to use eggs from the endangered Asian elephant and use the endangered African elephant as surrogates. For every elephant being used to create an elephant-mammoth hybrid we lose the opportunity to increase the populations of these endangered species. The money and expertise being put into de-extinction efforts may well be better served elsewhere, and to assume that just because there will be advances does not prove that this path is the best way to make those advances.
The Wow Factor
This is, frankly, a terrible argument. And it betrays the fact that for all the talk of ecological restoration and righting wrongs, the real reason for bringing back species such as the woolly mammoth is that people would pay money to see them. These are, after all, commercial ventures, and they need to make a profit. That’s why we see projects trying to resurrect the passenger pigeon but not the Rocky Mountain locust. A paper by Douglas McCauley and colleagues worked out which species make good candidates for de-extinction on ecological grounds and found that neither the woolly mammoth nor the passenger pigeon met their criteria. Instead they proposed that focus should go to The Christmas Island pipistrelle bat (Pipistrellus murrayi), the Reunion giant tortoise (Cylindraspis indica) and the lesser stick-nest rat (Leporillus apicalis). But hardly anyone will pay money to see a rat, so it stays extinct.
Conclusions
I have barely scratched the surface of the problems facing de-extinction proponents. I can understand why de-extinction appeals to so many, but the arguments made by its supporters do not hold up to scrutiny. De-extinction is not an ecologically sound method of conservation. It ignores the real problems that our planet is currently facing – habitat destruction and climate change.
We have many amazing species going extinct before our eyes. If we truly think we have a moral duty to make amends for our actions, our priority must be on saving as many of these species as we can. Anything else is a distraction.
