‘Humans play God all the time’: The biotech firm on a mission to bring back extinct animals
From the dodo to the Tasmanian tiger, the race to resurrect extinct species is heating up. It may be “playing God”, but one firm says there’s a life-and-death reason.
Some time around 40,000 years ago, the last diprotodon stomped its way across Australia.
A relative of the wombat and the koala, the diprotodon was the size of a small car — the largest marsupial to ever live — and one of the most widespread of Australia’s now largely extinct megafauna species.
For Professor Andrew Pask, the car-sized wombat would be one of his dream animals to bring back from the dead.
“I think that would be incredible — they’re just amazing animals,” he says.
“They were like ecosystem engineers. So they would dig up the dirt a lot … that would really promote the growth of different trees and shrubs.”
Prof Pask is not just daydreaming.
He’s the chief biology officer at Colossal Biosciences, a Texas-based biotechnology and genetic engineering company that has been at the forefront of so-called “de-extinction” research, working to resurrect the likes of the woolly mammoth, the Tasmanian tiger, the northern white rhinoceros, the dire wolf, the dodo and the moa.
The company made headlines earlier this year when it revealed footage of three dire wolf pups named Romulus, Remus and Khaleesi, in what it described as the world’s first-ever de-extinction.
Dire wolves — popularised by the HBO fantasy series Game of Thrones — disappeared from North America around 13,000 years ago. Dire wolves are 25 per cent larger than their grey wolf counterparts, with more muscular jaws and shoulders.
Colossal Biosciences said it created the three pups by combining ancient DNA extracted from dire wolf fossils with genes from their closest living relative, the grey wolf.
The modified genetic material was then inserted in a grey wolf egg and implanted in a common dog as a surrogate mother.
Prof Pask has revealed how this became a reality.
“It starts off with needing that set of instructions to build your extinct species,” he says.
“You’ve got to get that, which is their genome or their DNA. So we find fossil specimens or museum specimens of these particular animals. We’re able to get DNA from that. It’s something we’re really, really good at now is reading that DNA even from very, very old specimens. And then from that, you get the complete blueprint of how to build your extinct species.”
However “once we have that, we still can’t use that to bring the animal back”.
“We can’t just magically reanimate the cells or use those museum specimens to recreate life — so we have to start still with something living,” he says.
“So we use that DNA blueprint to say, ‘What is alive that is the closest living relative to our extinct species?’ And then we compare those DNA codes. And in most cases, these relatives are something like 99 per cent or more the same in terms of their DNA code. So then we have to edit that 1 per cent that’s different in living cells from that living animal.”
At that point, “you’ve recreated that extinct species”.
“And then once you’ve done that, we can use standard cloning technologies like we do to make Dolly the sheep and other cloned animals to turn that cell back into that extinct species,” Prof Pask says.
“That’s the very shortened version. Obviously it’s very complicated and there’s a lot of work involved, but that’s the basics of the nuts and bolts of it. And that doesn’t matter whether we’re thinking dodo or mammoth or thylacine. They’re all the same.”
At the time of Colossal Biosciences’ dire wolf announcement, some experts were sceptical.
“I think the claims are vastly overblown,” Alan Cooper, an evolutionary molecular biologist who took part in a previous study of dire wolf DNA, told AFP.
“It would be like me putting a couple of genes into you from Neanderthals that made you extra hairy and grow more muscles, and then called you a Neanderthal. That’s a million miles from Neanderthal. It’s a hairy human.”
Lisette Waits, an ecologist and professor of wildlife resources at the University of Idaho, agreed that while the achievement was a breakthrough, “This is not the dire wolf. This is something they have created that has phenotypic characteristics of dire wolf.”
Beth Shapiro, the company’s chief science officer, insisted whether the animals were actual dire wolves or simply genetically modified gray wolves was “a semantic, philosophical argument”.
She added that it would never be possible to create an animal that was 100 per cent genetically identical to a species that is extinct.
“But neither is that the goal,” she told AFP. “Our goal is to create functional equivalents of those species.”
According to Prof Pask, one of the key goals of Colossal Biosciences in bringing back extinct species would be to reintroduce them to aid in re-balancing the natural ecosystem and conserving the living creatures that already exist — especially those that are now endangered.
“De-extinction science is conservation science,” he says.
He argues the “current set of conservation tools we’ve had for a very long time” were no longer sufficient.
“We’ve lost too many species that we need to replace,” he says.
“We’ve lost big populations of animals as well. So even where we’ve got animals left, now we’ve reduced down that population size to such a tiny little group that thinking that we can, you know, just save the environment now and they will eventually repopulate that area, it’s going to take hundreds of thousands of years if we naturally expect them to re-evolve back into all these different ecosystems.”
De-extinction technology could be used to put “genetics back into those populations”.
“For living animals, we can make them really healthy and robust again so they can occupy bigger areas, hopefully when we save the planet,” he says.
“And we can bring back some of these species that, you know, we realised too late how important they are and they’d already gone, but now we can actually use it to reverse it.”
Prof Pask said there were “different reasons” to bring back any species.
“With the dire wolf, for example, we really developed a lot of technologies around canid biology or working with different species of wolves,” he says.
“And so the technology that was used to bring back the dire wolves was actually used to then reinvigorate the genetics of the red wolf population, which is the most endangered wolf population in the world. They’d lost a lot of the genetic uniqueness that make that population healthy. So using the technology that was made to make the dire wolves, they actually use that to make a much stronger, healthier population of red wolves, which was a fantastic outcome from that project.”
Similar de-extinction projects “also have applications to help preserve more species”.
“Quolls are dying in Australia,” he says.
“One of our next species probably to go extinct in the wild is the northern quoll, and that’s because they’re being killed from cane toads. They eat cane toads, they’re toxic, they die from cane toad toxin. But we figured out there’s just a single base pair, single bit of code that we need to edit in their genome to make them completely resistant to cane-toad toxin. That will save the quoll from extinction, but then they can actually eat bloody cane toads, which is even better.”
For Australians, perhaps no extinct animal captures the imagination more than the Tasmanian tiger, which disappeared in the early 20th century.
Colossal Biosciences has teamed up with the University of Melbourne’s Thylacine Integrated Genomic Restoration Research (TIGRR) group to bring the animal back to life.
Prof Pask, who is “completely obsessed with the thylacine”, believes reintroducing the species would be more than just a matter of national pride — it could be the key to saving another Aussie icon.
“I love them all, it’s just the thylacine is the one that I’ve been thinking about since the early 2000s in like, how do we actually go about doing this?” he says.
“Our closest living relative to the thylacine is a mouse-sized marsupial called the fat-tailed dunnart, so that’s the one that we’re engineering to bring back our thylacine. But also it’s probably going to be the surrogate mum to our first thylacines.”
That’s only possible because marsupials are born so small — about the size of a grain of rice — meaning even a tiny fat-tailed dunnart can give birth to a baby thylacine.
The baby would then be hand-reared with synthetic milks, already widely used in raising orphaned marsupial pouch young.
“The thylacine [was] obviously very near and dear to us … but that animal played an absolutely critical role in stabilising the ecosystem in Tasmania,” Prof Pask says.
“Not only did we lose this incredibly unique species, but we know that other species there are really struggling as a result of that animal missing from the landscape. Tasmanian devils have nearly gone extinct because they’ve got this terrible facial tumour disease, but when the Tasmanian tiger was around, it kept that disease in check. It would remove the sick animals from the population and stop that disease from spreading. It’s only in the absence of the thylacine that then this disease has now nearly driven the Tasmanian devil to extinction.”
Despite the successes in the de-extinction field, it has also raised obvious ethical questions, with accusations the science is unnatural and profit-driven.
Thirty-five years on from Jurassic Park, science fiction author Michael Crichton’s cautionary tale about man playing God that spawned the blockbuster film series, Prof Pask insists the technology is governed by “very rigorous ethics”.
He stresses it’s “all conservation focused” with the goal of saving species.
“‘Playing God’, you get that from time to time,” he says.
“But, you know, as humans, we do this all the time. We certainly played God when we hunted each of these species to extinction. Now it’s the point of using this technology in a thoughtful and responsible way to bring back some of those really important species to rebuild that resilience into these ecosystems. So I think if you see it as playing God, at least we’re doing good God work now as opposed to bad when we wiped everything out.”
Colossal Biosciences is “very careful about thinking of what unintended consequences might happen from doing this”.
“Really studying these species in great depth thinking about how we would thoughtfully try and rewild them back into certain areas of the planet again,” he says.
“How we would make sure they’re having these positive benefits on these ecosystems. So there’s things that we can really do to make sure we’re doing this in a very responsible and thoughtful way.”
Indeed, the firm has claimed that its technology could be crucial to sustaining life on earth over the next century.
“When those ecosystems fall apart our world falls apart,” Prof Pask says.
“Like it’s only a matter of time. And the thing is now we know it’s actually too late. We’re in the middle of the sixth mass extinction. We’ve already reduced wildlife by over 50 per cent in the last 50 years. We absolutely have to embrace this new technology if we want fix some of these mistakes ... we have to really understand the good, not be frightened about these technologies, but listen to the really good science behind it.”
Originally published as ‘Humans play God all the time’: The biotech firm on a mission to bring back extinct animals
