De-extinction is a fairytale

The moa lives through pixels and possibilities. AI-generated image by Huata Arahanga.

There has been a resurgence in discussions of de-extinction, also known as resurrection biology or species revivalism. Discussions were sparked by the news that the biotech company Colossal Biosciences has ‘resurrected’ the dire wolf, a ‘species’ from the American continent that became extinct some 13,000 years ago.  

The ‘promise’ of de-extinction has led to people in decision making roles in U.S. government agencies to question the need to put money into protecting threatened species and the ecosystems they inhabit. As researchers working to make meaningful impact in conservation, it is alarming to see how this fad may draw resourcing and attention away from pressing conservation needs. But there’s more: the whole process of de-extinction is not technically possible.

De-extinction through genetic editing sounds plausible and desirable because who doesn’t want to see these magnificent animals in the flesh? Most of us have an animal we’d love to see from the past (for us it would be Pouākai or Haast’s eagle). But let’s put this into a technical context. The dire wolf wasn’t just one species, they were two sub-species with slightly different genomes. The closest living relative of the dire wolf is the gray wolf. But these species diverged from a common ancestor more than 5 million years ago and since then have become different lineages, with each species having a genome size of 2.5 billion base pairs long (for reference, the human genome has approximately 3.2 billion base pairs).

There are thousands if not millions of differences between dire wolf and gray wolf genomes due to evolutionary mechanisms making slow, subtle changes over millions of years. But we don’t know what all these differences are because there isn’t enough dire wolf genetic material around anymore to create a high-quality full genetic sequence.

What Colossal Bioscience has done to resurrect this (these!) species is edit 15 genes in gray wolf embryos and implant those edited embryos back into a gray wolf mother, who carried these to full term. In essence, they have created a genetically modified gray wolf, not a dire wolf.

If these genetic facts aren’t convincing enough, consider that DNA isn’t everything. Oocytes, eggs, are complex structures, patterned and organised by the mother that makes those eggs. Eggs contain information that trigger genes to be turned off or on in particular places, they contain information crucial for the development of an embryo. Where this has been studied carefully, we know that this structured information evolves fast. Dire wolf oocytes descended, in an unbroken line, from the last dire wolf female. That chain of inheritance was broken when the last dire wolf died. You cannot, with current technology, build a dire wolf oocyte, and thus, you cannot bring back a dire wolf.

Extinct taonga species of Aotearoa have also been included as subjects in these discussions.  But just like the dire wolf, resurrecting the moa would be technically impossible. We don’t have moa eggs, we don’t have good moa genomes, and likely never will. We don’t have a close relative that we could even use as a surrogate.

Even more important, the habitats we have remaining to support the native species that are still alive are diminishing; so, what environment do we have left to share with a resurrected population of moa? And even if we were to re-introduce extinct species back into current ecosystems, how would their behaviour and interactions with other species (including humans) play out? Going back to the recent resurrection, gray wolves have a complex society, as many dogs and wolves do. We assume dire wolves did too. It is not clear that social behaviour is all inherited through DNA – certainly in humans we would say it’s not.  So, would these edited wolves, now in a state of ecological and social confusion and lacking the learned behaviours of their parents, ever act like dire wolves?

It’s not the absurd impossibility of this endeavour that bothers us the most. For us, it’s the lack of ethics. In Aotearoa New Zealand, we have hundreds, if not thousands, of species that are facing extinction.

Preserving these species is hampered by a lack of focused long-term research and management in areas such as pest control and habitat restoration. It is unethical to bring species back when we haven’t even found ways to save the species we still have.

It is also unethical to leave those of us working to save and improve on what remains struggling to find the tools and resources necessary to succeed all for the sake reinventing species that died out well before the human interferences that have characterised the Anthropocene. Bringing back three ‘dire wolves’ cost Colossal Biosciences $435 million in USD. That’s nearly $738 million in New Zealand currency. The annual budget of Te Ata Papawhai / Department of Conservation was $675 million NZD for the 2024/25 financial year. What could be done with, say, the price of just one ‘dire wolf’ pup ($245 million NZD)? For starters, at $90 million we could see a pest free Rakiura/Stewart Island within 5 years. This would see the eradication of invasive species like rats, mice, and feral cats, allowing many native and threatened species to thrive. With the remainder, we could invest in many other eradication programmes as well as waterway and wetland restoration projects.

Conservation is where we should be spending our limited and diminishing resources. By preserving our taonga species now, we wouldn’t be put in a position to have to bring them back later at considerable expense and effort.

Our hope is that the de-extinction movement is quickly consigned to a dark part of history – a lesson to learn from in what not to invest in. Because biodiversity and ecosystem resilience are in severe trouble. We need to concentrate on saving the taonga species we have and, importantly, the places they need to thrive. Resourcing and tools are scarce, and we need to make decisions that will have the greatest, intergenerational impact that considers the ecosystem as a whole and the taonga species that live here.

Author
Amanda Black – Director, Bioprotection Aotearoa

Guest Contributors
Peter Dearden – Director, Genomics Aotearoa
Thomas Buckley – Principal Scientist, Systematics, Manaaki Whenua – Landcare Research