In a world-first, US biotech firm Colossal Biosciences has created three wolf pups with physical traits of the long-extinct dire wolf. Using advanced CRISPR gene-editing technology, the team modified gray wolf DNA to mimic that of the legendary predator, which vanished over 10,000 years ago. The pups, named Romulus, Remus, and Khaleesi, were born after scientists implanted edited DNA into dog embryos. While hailed by some as a leap in de-extinction science, experts caution that these animals are hybrids—not real dire wolves.
A Genetic Milestone: Bringing Back Lost Traits
Colossal’s team used CRISPR to alter 20 targeted DNA sites in blood cells taken from living gray wolves. The changes were based on dire wolf DNA recovered from fossils in Ohio and Idaho. Scientists studied a 13,000-year-old tooth and a 72,000-year-old skull to identify unique features of the extinct species.
The resulting pups have long white fur, broad jaws, and faster-than-normal weight gain. These are all traits associated with the dire wolf, which once roamed North America and was much larger than today’s wolves.
To create the animals, scientists inserted modified genetic material into egg cells from domestic dogs. They then implanted those eggs into surrogate dogs. After a 62-day pregnancy, the gene-edited pups were born healthy.
Experts Question the Term ‘De-Extinction’
Despite the breakthrough, scientists outside the project urge caution.
Vincent Lynch, a biologist and geneticist, said these pups are not true dire wolves. “Just because something looks like a dire wolf doesn’t mean it is one,” he explained. Cloning, not gene editing, would be required for a true resurrection, and cloning remains impossible due to the poor quality of ancient DNA.
Nic Rawlence of the University of Otago agreed. He said creating hybrids based on a partial genome is not the same as reviving a lost species. DNA from extinct animals is usually too degraded for full reproduction. Instead of restoration, the process produces genetic imitations.
Beth Shapiro, Colossal’s chief scientist, confirmed this. She said the goal was never to clone a dire wolf, but to engineer wolves with similar traits. That distinction matters, according to critics. Without wild-born parents to teach survival skills, the pups won’t act like dire wolves either.
“These animals will not fill the same ecological role,” Lynch added. “They can’t hunt or behave like the real thing.”
Blending Science with Conservation Goals
Colossal is not stopping with dire wolf traits. The company has larger ambitions, including bringing back the woolly mammoth and the dodo. It recently cloned four red wolves using DNA from endangered wild populations to improve genetic diversity in captive breeding programs.
CEO Ben Lamm defended the company’s efforts. He told Euronews Green that de-extinction and conservation are closely linked. “Preserving species and reviving extinct ones share the same tools and goals,” he said.
Wildlife ethicist Christopher Preston noted that CRISPR editing is less harmful than traditional cloning. But he acknowledged the ethical concerns. Collecting blood samples from wild wolves requires sedation, which is invasive and stressful for the animals.
In March, Colossal held talks with the U.S. Interior Department. Secretary Doug Burgum praised the project online, calling it a “new era of scientific wonder.” Still, independent scientists stress the need for realistic expectations.
What Comes Next?
While the birth of dire wolf-like pups marks a new chapter in genetic science, researchers emphasize that re-creating a true extinct species remains out of reach—for now. These hybrids may help scientists better understand evolution and adaptation. But they won’t restore lost ecosystems or erase extinction.