In certain instances, we may earn revenue when a reader makes a purchase or completes a form through our pages or on a partner’s website. We adhere to a strict 
A US biotech firm shocked the world in April 2025 with claims it had brought the long-extinct dire wolf back from oblivion – resurrecting the mysterious uber canine lionized in the popular fantasy series “Game of Thrones.”
The company used CRISPR gene editing technology to make targeted changes to modern grey wolf DNA, effectively mimicking some of the dire wolf’s distinctive genetic traits.
So while it’s not quite Jurassic Park, it does offer hope that our evolutionary forbears could walk amongst us again.
Will CRISPR help recreate other lost species? We examine how it works, consider what’s coming next, and explore the future of CRISPR gene editing.
Key Takeaways
- A US biotech company says it has resurrected an extinct canine species called the dire wolf, using a sophisticated gene editing technique.
- The firm examined ancient dire wolf DNA samples and mapped its genome, noting its similarity to modern gray wolf DNA.
- Scientists then edited gray wolf DNA with dire wolf traits and inserted the re-engineered nucleus into a healthy gray wolf ovum.
- It’s not cloning exactly, but it offers a tantalizing glimpse of Earth’s evolutionary past, with more set to come.
Dire Wolves Brought Back: A Return to the Biological Past
Evolution brought the dire wolf to life two-and-a-half million years ago before extinction took it away.
The species died out in the final millennia of the Pleistocene era – some 10,000 to 13,000 years ago – but now it’s back, ready to prowl 21st-century plains thanks to the work of Colossal Biosciences, a Texas-based biotech company leading the charge in dire wolf de-extinction.
On April 7, 2025, the firm said it had used a blend of traditional cloning and CRISPR-based genome editing to birth three ‘dire wolf’ pups, two males named Romulus and Remus, and a female named Khaleesi, a reference to Game of Thrones.
Using samples of ancient dire wolf DNA (aDNA), Colossal was able to inject dire wolf traits into a grey wolf ovum, effectively overlaying some of the extinct species’ characteristics onto a distant relative’s DNA strand.
It relied on CRISPR tech, short for “clustered interspaced short palindromic repeats.” The advanced gene editing technique leverages a mechanism used by microbes to help find and eliminate unwanted invaders. Simplified versions of it are even available in consumer-level CRISPR gene editing kits for educational purposes.
When a virus or other infection enters a bacterial cell, the bacterium incorporates some of the trespasser’s DNA into its own genome, making it easier to track down and eliminate during future infections. CRISPR copycats that process to insert specific chromosomes into a recipient ovum’s DNA, altering its physical characteristics when fully grown.
Embracing tradition as well as pure science, Colossal partnered with North Dakota’s indigenous MHA Nation, which places spiritual significance on the dire wolf and hopes to see it roam again on their traditional lands.
Mark Fox, Tribal Chairman of the MHA Nation, said the return of the dire wolf “represents the return of an ancient spirit.” The dire wolf, he said, “carries the echoes of our ancestors, their wisdom, and their link to the wild.”
The dire wolf de-extinction project is as much a cultural milestone as it is a scientific one. Quoting science fiction author Arthur C. Clarke, Colossal CEO Ben Lamm noted: “Any sufficiently advanced technology is indistinguishable from magic.”
“Today, we reveal some of the magic we’ve been working on,” Lamm said.
What Is CRISPR Gene Editing?
Cloning, the process of transferring the nucleus from one embryo into another de-nucleated (nucleus removed) embryo, has been used to successfully create exact copies of a wide variety of species, from tadpoles to primates. In 1996, it gave us Dolly the Sheep, the first public clone of a large mammal.
To clone an organism, a single cell is drawn from a tissue sample. The cell’s nucleus, which stores the organism’s complete genetic code, is then removed and placed into a de-nucleated ovum (embryonic cell) taken from the same species.
The ovum is then left to grow into a full embryo before being transplanted into a healthy female surrogate. The female eventually gives birth to the clone, an exact duplicate of the animal from which the donor nucleus was taken.
CRISPR technology works differently. Colossal’s gene scientists first extracted dire wolf DNA from an ancient tooth and skull, then analyzed the genetic code within.
Comparing the dire wolf’s DNA to that of its closest modern relative, the gray wolf, Colossal’s scientists identified 20 differences that set the dire wolf apart, particularly its lighter fur pigmentation and larger overall size.
The gray wolf’s ancient forebear had a bigger head, longer teeth, more muscular legs and shoulders, and even howled differently.
Next, they harvested cells from the lining of gray wolf blood vessels, then re-coded the gray wolf genes by writing dire wolf traits into their nuclei.
Potential Complications
That top-line description barely skims the surface of the highly detailed, complex technical processes behind CRISPR. Editing genes is incredibly difficult and can lead to unintended consequences.
In the press release announcing the breakthrough, Colossal noted that the dire wolf genes responsible for its white fur can cause deafness and blindness in gray wolves. To avoid this, Colossal scientists designed two new genes that removed the chromosomal triggers for red fur and black fur, leaving the dire wolf’s distinctive white color by default and avoiding any harm.
After being edited, the rewritten gray wolf nuclei were extracted and injected into a series of nucleus-free gray wolf embryonic cells. These were then left to grow into full embryos that were implanted into surrogate female dogs.
Following a 60-day gestation period, Rolulus and Remus were born, followed by Khaleesi a few months later. All three were born using scheduled cesarean sections to reduce the chances of injury during delivery. Across the process, none of the dire wolf mothers experienced a miscarriage or stillbirth.
The Bottom Line
While the apparent resurrection of a long-extinct species is a major scientific breakthrough, it has to be noted that the dire wolf de-extinction is really the genetic alteration of a modern gray wolf, not a clone or duplicate of the species that last walked the Earth 10,000 years ago.
Still, the results are astounding, and Colossal plans to use similar techniques to ‘bring back’ the woolly mammoth, or express its signature traits by editing the cell nuclei of Asian elephants, the mammoth’s closest living relative.
In early March, the company said it had conducted a successful early trial in laboratory mice, creating 35 ‘woolly’ mice with the mammoth’s distinctive shaggy coat. Now, Colossal says it expects the first surrogate pregnancy to start in 2026, with a successful birth in 2028 after the elephant’s standard 24-month gestation term.
It’s not quite Jurassic Park, but the firm’s breakthroughs in CRISPR technology could see more extinct species back for another evolutionary go.
FAQs
How does traditional gene therapy compare to CRISPR-Cas9 genome editing?
Is CRISPR gene editing in humans possible today?
Has CRISPR cured anyone?
Have dire wolves been brought back to life?
References
- Solving the Colossal Problem of Extinction (Colossal)
- Press Release Service: Colossal Announces World’s First De-Extinction: Birth of Dire Wolves (CRISPR Medicine)
- Stanford explainer: CRISPR, gene editing, and beyond (Stanford Report)
- The History of Cloning (Learn Genetics)
- The story of Dolly the sheep (NMS)
