In a world-first announcement that blurs the line between science fiction and reality, Dallas-based biotech firm Colossal Biosciences claims to have resurrected one of North America’s most iconic Ice Age predators: the dire wolf*. But while the headlines are dramatic, the truth behind the science is more complex and controversial.
The Science Behind the Revival
Scientists extracted DNA from fossilized dire wolf remains to create a complete genetic blueprint or genome. This genome allowed them to identify essential alleles that contributed to the dire wolf traits.
They then compared the dire wolf’s DNA to that of living dog-like animals, especially gray wolves. This comparison enabled researchers to identify around 20 genes that affect traits such as bone structure, skull shape, muscles, metabolism, and fur.
Using the gene-editing tool CRISPR-Cas9, scientists inserted the dire wolf genes into the DNA of gray wolves. In this first round, they successfully edited 14 of those genes.
Next, they used somatic cell nuclear transfer (SCNT). They introduced the modified DNA into egg cells after removing their original DNA. These eggs were then implanted into regular dogs to carry the pregnancies. Out of 45 viable embryos, two puppies, Romulus and Remus, were born through C-sections on October 1, 2024. A third pup, Khaleesi, was born on January 31, 2025.
One month old dire wolf twins Remus and Romulus.
Even though the puppies had dire wolf genes, the scientists knew that other factors, like environment and how the genes turn on or off (called epigenetics), would also affect how they developed. The pups might not grow up like real dire wolves. From the moment they were born, the puppies displayed behaviors that reflected their wolf ancestry. They were alert, made stalking movements, and started vocalizing early. However, it’s still too soon to know how closely their behavior will match that of ancient dire wolves.
Khaleesi, the first de-extinct female dire wolf.
Scientists Push Back: “They’re Not Dire Wolves”
Despite Colossal’s bold claims, the engineered animals are, at best, a tribute to the extinct species, not a true resurrection.
“Calling these animals ‘dire wolves’ is misleading,” said paleogeneticist Dr. Nic Rawlence. “Dire wolves split from gray wolves millions of years ago. Editing a few genes doesn’t erase millions of years of evolutionary divergence.” Other experts note that while the scientific achievement is impressive, it is more akin to creating a lookalike than bringing a species back from extinction.
Ethical and Ecological Red Flags
Beyond the genetic debate, critics are raising ethical concerns. De-extinction efforts may divert resources from protecting endangered species.
“What happens if these engineered wolves are released into ecosystems they never evolved to inhabit?” asked environmental ethicist Dr. Lena Cheng. “There’s a real risk of unintended ecological consequences.”
Colossal maintains that the project is both a scientific milestone and a potential tool for conservation. The company is simultaneously pursuing other high-profile de-extinction goals to restore ecological balance, including efforts to revive the woolly mammoth for areas like the Arctic tundra.
A Glimpse of the Future
Romulus, Remus, and Khaleesi live in a high-security enclosure under observation by a team of geneticists, behaviorists, and veterinarians. Whether these pups represent the beginning of a new era in conservation biology or a cautionary tale of scientific overreach remains to be seen. What’s certain is that the return, or recreation, of the dire wolf has reignited public fascination with a species that once roamed alongside saber-toothed cats and mastodons.
Ben Lamm, chief executive of Colossal, with a dire wolf pup.
*While the wolves are not true dire wolves, they will be referred to as such for the article’s simplicity.
Works Cited
Clayworth, Jason. “How a Des Moines Professor Helped De-Extinct the Dire Wolf.” Axios, Axios Des Moines, 10 Apr. 2025, www.axios.com/local/des-moines/2025/04/10/dire-wolf-desmoines-professor-genetics-extinction. Accessed 10 Apr. 2025.
Kluger, Jeffrey. “The Return of the Dire Wolf.” TIME, Time, 7 Apr. 2025, time.com/7274542/colossal-dire-wolf/.
—. “The Science behind the Return of the Dire Wolf.” TIME, Time, 7 Apr. 2025, time.com/7275439/science-behind-dire-wolf-return/.
Pilcher, Helen. “Have Researchers Really ‘De-Extincted’ the Dire Wolf? No, but behind the Hype Was a Genuine Breakthrough.” The Guardian, The Guardian, 10 Apr. 2025, www.theguardian.com/commentisfree/2025/apr/10/de-extincted-dire-wolf-hype-breakthrough-grey-wolves. Accessed 10 Apr. 2025.
Schlosberg, Jon, et al. “Dire Wolf Revived through Biotech Company’s De-Extinction Process.” ABC News, 7 Apr. 2025, abcnews.go.com/US/dire-wolf-revived-biotech-companys-de-extinction-process/story?id=120558562.
Staff, Al Jazeera. “Has the Dire Wolf Come back to Life? Here Is What We Know.” Al Jazeera, 8 Apr. 2025, www.aljazeera.com/news/2025/4/8/has-the-dire-wolf-come-back-to-life-here-is-what-we-know.