Yes, we should bring back the Dire Wolf-but is this it?

Romulus. Pic: Colossal Bioscience. The Dire Wolf was a formidable predator that lived during the Late Pleistocene epoch (approximately 250,000 to 10,000 years ago). Though often compared and superficially similar to the modern Gray Wolf (Canis lupus), was a distinct species with unique characteristics.

It begins with a ghost. Or rather, the idea of a ghost — a shape in the mist of deep time, reconstructed from fragments: a tooth, a bone, a strand of ancient DNA. The dire wolf, Aenocyon dirus, was a creature of the Pleistocene epoch — larger and stockier than today’s grey wolf, more powerful in jaw and limb, more bone-crushing in its bite. It walked the Americas for millennia, vanishing some 10,000 years ago alongside mammoths, giant sloths, and sabre-toothed cats in a wave of extinction that swept the planet.

Now, it returns — or something like it does. In 2024, Colossal Biosciences, a Texas-based genetic engineering company, announced the birth of three pups modified to exhibit “dire wolf traits.” Named Romulus, Remus, and Khaleesi, they are not clones, nor true revivals. Rather, they are grey wolves, subtly altered — around 20 genes tweaked using CRISPR technology — to approximate the lost form. The world, understandably, took notice. “Dire wolf de-extincted,” the headlines declared. But behind the bold proclamations lies a more nuanced, perhaps more poetic truth: what makes a dire wolf a dire wolf?

A view of a very young ‘Dire Wolf’ pup, showcasing a fluffy white juvenile coat in its early stages of life.

It is a question of biology, yes, but also of philosophy — of essence and expression, identity and imitation. It touches not only on genetics but on memory, on the moral weight of extinction and the deep human desire to undo our severings.

Species as shadows: the trouble with definitions

Where one species ends and another begins is a line drawn not in nature, but in us. In textbooks, species are boxed and labelled: Canis lupus, Panthera leo, Homo sapiens. But nature seldom respects such boundaries. Genes flow. Hybrids abound. Wolves and coyotes interbreed. Lions and tigers can produce ligers. Even humans, supposedly the sole survivors of our genus, carry traces of those we outlived. Non-African populations of Homo sapiens carry 2–3% Neanderthal DNA. Some Asian groups also carry genes inherited from the Denisovans. There is evidence, too, of a ghost lineage — perhaps Homo erectus — lingering in certain populations.

We are, all of us, palimpsests.

To call something a dire wolf, then, is to engage in taxonomy — a practical necessity, but also a cultural and ethical act. The dire wolf was not simply a scaled-up grey wolf. A 2021 study analysing ancient DNA from dire wolf fossils found that they diverged from the lineage of grey wolves, coyotes, and dogs around 5.7 million years ago. They were not even members of the Canis genus. Instead, they belong to a separate branch entirely: Aenocyon, meaning “terrible wolf.”

They could not interbreed with grey wolves. Their genome was a stranger’s song.

Colossal has sequenced the dire wolf genome. If they can prove their data, they may offer new insights. But until then, the scientific consensus holds: the dire wolf was not a close cousin. It was another creature entirely.

So what, then, are Romulus, Remus, and Khaleesi?

They are grey wolves, genetically modified. Beautiful animals. Groundbreaking symbols. But not — not yet — dire wolves.

This phylogenetic tree depicts the evolutionary relationships among various canid species, highlighting the position of the extinct Dire Wolf (Canis dirus/Aenocyon dirus) within the dog family and their estimated divergence times in millions of years.

A mirror, not a resurrection

And yet, the achievement is extraordinary. To look upon a living creature that recalls the dire wolf in bearing and shape is to feel the tug of deep time. The genes modified were selected for traits we associate with the dire wolf: size, strength, coat colour, metabolic function. But only around 20 genes were altered. A typical mammalian genome contains over 20,000. We are in prototype territory.

The analogy has been made to launching rockets. The early ones failed, again and again. But they laid the groundwork for orbit, and for moonlight footfalls. Colossal’s wolves are not a finish line. They are a first launch.

Still, words matter. Calling them “de-extincted” risks public misunderstanding. It invites cynicism. Science suffers when the distance between truth and marketing grows too wide. And yet, we must also admit: storytelling matters too. Colossal needs headlines to attract investors. Without funding, the work stalls. Progress slows. Perhaps it is a necessary tension — between ambition and accuracy, between symbol and substance.

Of ghosts and ecologies: why bring a predator back?

To ask whether we should bring back the dire wolf is to ask what we owe to the world we’ve lost. Ecologically, the argument is compelling. Predators structure ecosystems. Their absence leaves a void.

Look to Yellowstone. When wolves were extirpated in the 1920s, deer populations surged. Coyotes remained, but could not control them. The landscape suffered. Riverbanks eroded. Saplings vanished.

A visual comparison of Blacktail Deer Creek in 2005 and 2021, clearly demonstrating the expansion of riparian vegetation along the stream banks over a 16-year period thanks to the wolf introduction reducing overgrazing

Songbirds declined. Then, in 1995, wolves were reintroduced. The cascade began. Fewer deer meant more willows and aspens. More trees meant more nesting birds, more beavers, more stability in the soil. Rivers changed course. The land healed.

This is the power of trophic cascades. Wolves shaped forests with their absence as much as their presence.

Now imagine a predator above even the grey wolf — a heavier, more powerful carnivore adapted to hunt the largest prey of its age. That was the dire wolf. Its diet likely included bison, horses, ground sloths — species that, in many cases, are themselves extinct.

Yet others remain. Elk. Moose. Bison. Could a proxy-dog, dire in form and function, help to re-balance what has been unbalanced for ten millennia?

Perhaps.

But ecosystems are not static dioramas. They are dynamic, responsive, evolving. The prey of the dire wolf is not what it was. Nor is the climate. Nor are we. The reintroduction of a top predator, especially one approximated from the past, must be done with the utmost care. Pleistocene Park in Siberia offers one such model: a place where large grazers are being reintroduced to restore ancient grasslands, and where, one day, scientists hope to reintroduce mammoths — or their closest living analogues.

It is not science fiction. It is science, tested slowly, in the field.

The botanical memory of megafauna

There is another reason to consider the return of such creatures — one less often spoken of, but deeply evocative. The plants remember.

The spiky armour of gorse (Ulex europaeus), a plant whose fierce thorns may have evolved to deter long-vanished megafauna. These defenses linger as a ‘botanical memory’ of extinct herbivores, showcasing how ecosystems retain echoes of species lost to time—a stark reminder of extinction’s ripple effect on plant evolution.

Scattered through our landscapes are species with traits that no longer make sense. Take the hawthorn, its limbs bristling with long, defensive thorns. Or holly, whose lower branches are spiked while upper boughs are left smooth. Gorse — all spine and defiance. These are anti-herbivore adaptations, but far in excess of anything needed to deter red deer or sheep. So who were they built for?

Palaeobotanists suggest an answer: extinct megafauna. European elephants. Woolly rhinos. Even in Ireland and Britain, the flora still holds its armour against creatures it has not seen in 10,000 years. Their spines are signatures of a forgotten ecology. The plants have not caught up. In a way, they still believe the giants walk among them.

This is more than speculation. In the Eemian interglacial — around 126,000 years ago — the world was warmer than it is today. Europe hosted not just rhinos and hippos, but elephants: Palaeoloxodon antiquus, the largest land mammal to have ever lived. These beasts helped shape forests, created openings, trampled paths, dispersed seeds. Their loss was not merely a subtraction. It was a reorganisation of everything.

And so the trees still bear their ghosts. The memory is written in bark and thorn.

The weight of absence: how extinctions reshape the world

We are accustomed to thinking of extinction as final — an end, a void. But in ecological terms, extinction is not an event. It is a process that ripples through systems, often for centuries.

Consider the mammoth. When mammoths disappeared, they took their ecosystem with them. The mammoth steppe — a vast, grassy expanse stretching from Portugal to the Bering Strait — collapsed. Some researchers suggest this collapse was not simply due to climate change, but due to the disappearance of the mammoths themselves. Their trampling, grazing, and nutrient cycling maintained that biome. Once their numbers fell below a threshold, the system unravelled. Trees encroached. Snow accumulated. The balance was lost.

This is known as an ecological runaway effect — when the loss of one element triggers the loss of many more.

Could the same have happened to the dire wolf?

Map showing the potential modern extent of the Mammoth Steppe, had Pleistocene megafauna survived.

Vast areas of what is now taiga forest and tundra — especially across northern Siberia, Alaska, and northern Canada — would instead be dominated by open grassland. This map illustrates how sustained grazing pressure from woolly mammoths, steppe bison, and other Ice Age herbivores could have maintained a continuous Mammoth Steppe across the Northern Hemisphere, reshaping much of today’s subarctic landscapes.

A vibrant depiction of the Mammoth Steppe, a vast and productive grassland that once stretched across the Arctic and subarctic regions, teeming with megafauna like the iconic Woolly Mammoth and the heavily built Woolly Rhinoceros.

It is possible. While direct human hunting of dire wolves seems unlikely, pressure on their prey may have sealed their fate. Large-bodied herbivores reproduce slowly. Even light predation — especially on calves — can reduce populations dramatically. As prey declined, so too did their hunters. Meanwhile, smaller, more generalist predators, like the grey wolf, adapted. The dire wolf, a specialist, did not.

And so the keystone fell.

Ecological substitutes and the ethics of analogy

If we cannot bring back the exact species, can we bring back the role it played?

This is the idea behind ecological substitution: introducing a different species that performs the same function. It has already been tested. In Australia, water buffalo — originally from Asia — were introduced to replace lost grazing pressure once exerted by extinct megafauna like Diprotodon, a giant wombat-like creature. Surprisingly, their presence has improved wetland health in some regions. They trample invasive vegetation, disperse native seeds, and maintain open grassland.

Of course, such introductions must be handled with immense caution. The annals of conservation are filled with well-intentioned disasters. The cane toad in Australia, introduced to control beetles, couldn’t reach them — but poisoned predators instead. In Hawaii, rats were followed by snakes to eat the rats, only for the snakes to feast on native bird eggs. Then came introduced mongooses to fix the snake problem — diurnal, unlike the nocturnal snakes — and the chaos compounded.

But megafauna are different. They are slow-breeding, visible, and relatively easy to manage. Their effects are large but often predictable. If introduced in trial settings, under strict monitoring, they can offer real insight.

Could lions be be reintroduced to North America to fill the niche of the extinct Panthera atrox, the American lion? Could cheetahs from Africa pursue the pronghorn, whose speed evolved to escape a predator that no longer exists?

These are not questions for the faint-hearted. But they are questions worth asking.

The first image depicts the American cheetah (now extinct) chasing a pronghorn—a surviving species of antelope in North America renowned for its incredible speed, which allows it to outrun most modern predators. Historically, the American cheetah was the pronghorn’s natural predator, playing a vital role in maintaining ecological balance by controlling the pronghorn population.

The second image shows an African cheetah, which, while not evolutionarily related to the American cheetah, occupies a similar ecological niche. Both species developed comparable lifestyles and physiological traits through convergent evolution—adaptations driven by similar environmental pressures rather than shared ancestry. Introducing a species like the African cheetah could potentially replicate the ecological role of the extinct American cheetah. This highlights that the health and balance of an ecosystem depend more on the ecological roles species fulfill (e.g., predator-prey dynamics) than on their specific genetic identities.

Colossal’s role, and the caution it must carry

Critics of Colossal argue that its projects are headline-chasing. That the science is preliminary. That calling a grey wolf with 20 altered genes a dire wolf is misleading.

They are right — in part.

But it is also true that Colossal has invested more in marsupial conservation in Australia than the Australian government. It is supporting efforts to preserve the northern white rhino. It has spoken of helping the endangered red wolf in the United States. For every de-extinction project, it claims, there will be a parallel effort to support a living species. If true, this represents a model where public interest in extinction funds real conservation.

What we talk about when we talk about GMOs

Much of the criticism aimed at Colossal’s wolf stems from one phrase: genetically modified.

A funny and wide-eyed tortoiseshell or calico cat experiences bath time, a far cry from the arid environments of the African Wildcat, the primary ancestor of all domestic cats.

The words arrive carrying weight — suspicion, discomfort, sometimes outright rejection. For many, the idea that something has been altered at the level of its DNA triggers an instinctive recoil. “It’s unnatural,” some say. “It’s playing God.”

But is it, really?

As I write this, a genetically modified African wildcat is curled in my lap. We call her a domestic cat. Her ancestors were shaped by human hands over thousands of years — her coat colour, her vocal cords, the very architecture of her skull, all altered by a slow, sprawling process of selection. Not in a lab, not with CRISPR, but with the same intent: to create an animal that met our needs.

Wheat is genetically modified. So is corn. So are dogs — perhaps the most extreme case of human-driven genetic transformation in the animal kingdom. Some dogs, like pugs or bulldogs, are caricatures of their ancestral selves, altered almost beyond recognition. And yet they’re accepted — beloved, even.

The truth is, we’ve been genetically modifying animals for millennia. The only difference now is precision.

That doesn’t mean all genetic modification is good. It doesn’t mean we shouldn’t scrutinise new technologies. But we must also be honest about the history we’re part of. The natural world, as we experience it, is already filled with the fingerprints of our species. Rejecting an animal solely because it’s been modified is not a defence of nature — it’s a refusal to look closely at what nature has already become. And perhaps that is the point.

No one is suggesting that we abandon the protection of the living for the resurrection of the dead. But the technologies being developed — genome sequencing, cryopreservation, synthetic embryos — may be vital tools in preventing future extinctions. They can help us rebuild genetic diversity in small populations. Clone individuals where none remain. Reintroduce lost traits that once allowed species to adapt to changing climates.

They are tools. What matters is how we use them.

Memory, myth, and the meaning of revival

There’s something deeply human about the desire to bring back what’s been lost. It touches an ancient part of us — the part that stores stories in the bones of hills and hears the howl of wolves long after the last has vanished from the valley. The dire wolf, like the thylacine or the mammoth, has become more than an animal. It is an emblem. A symbol of absence. A question, howling across the divide: what if?

But we must tread carefully. Memory is not a blueprint. Myth is not a map. To recreate the past is not to restore it. We cannot bring back what was. Not perfectly. Not entirely. The ecosystems have changed. The climate has changed. We have changed. The best we can do is listen — to the land, to the science, to the stories held in the DNA of extinct creatures and the defensive arms of thorn trees.

And we must name things truthfully. The animals born in Colossal’s lab are not dire wolves. They are altered reflections — perhaps the first notes in a long composition. Perhaps not. But to call them what they are not does a disservice both to science and to the creature we claim to honour.

Still, there is value in what has been done. Immense value. We now stand on the cusp of being able to restore lost functions to broken ecosystems. To give back what we took. To move not backward, but forward — toward a new kind of wildness, shaped not by the past alone, but by imagination and humility and deep ecological thought.

In this work, the goal is not just to bring back the dire wolf. It is to restore the richness, the complexity, the balance that its absence disrupted. It is to bring back the weight of a predator’s step, the ripple of its presence through the prey herds and the forests, the howling thread of it stitched into the dusk.

We must remember that extinction is not just about what we lose.

Remus. Pic: Colossal Bioscience. This image highlights the features and habitat of a modern canid, offering a glimpse into traits that may echo those of the extinct Dire Wolf.

It is about what we take from everything that remains. Every vanished creature alters the whole. Every revival, if done wisely, can help to mend it.

So let us not chase ghosts blindly. Let us walk forward with our eyes open, with reverence and rigour, with stories in one hand and data in the other. The dire wolf may not yet return — not truly, not fully — but the very act of trying may teach us how to live better with what we still have, and how to listen for what the world still needs.

Because perhaps the question is not “what defines a dire wolf?” but “what do we become when we try to bring it back?”

And that, too, is a story worth telling.