De-extinction was big news in 2025 – but didn’t live up to the hype

Colossal Biosciences, which calls itself “the world’s first and only de-extinction company”, generated a lot of headlines this year. The hype, however, bore little relation to reality.

First, the US-based firm made a splash with woolly mice “engineered to express multiple key mammoth-like traits”. Victoria Herridge at the University of Sheffield, UK, pointed out on Bluesky the long hair of the mice whose photos were splashed all over the media wasn’t a result of gene edits based on mammoth DNA, and that geneticists have been creating long-haired mice for decades. The mice with more mammoth-related gene edits looked less mammoth-like.

Then came the big one: the world’s first de-extinction, according to the company’s press release. Colossal claimed it had brought back the dire wolf (Aenocyon dirus), a wolf-like beast that lived in the Americas before going extinct around 10,000 years ago. In fact, what Colossal did was make 20 small changes to the genome of grey wolf (Canis lupus) cells, only 15 of which were based on the genome of dire wolves, and then cloned the altered cells to produce three wolf pups.

As there are millions of genetic differences between the two species, this is a tiny step towards making grey wolves more like dire wolves. It’s a very, very long way from the Jurassic Park-style creation of exact genetic copies of extinct species.

Most media outlets reported the de-extinction claim unquestioningly. New Scientist was one of very few to flatly reject it: “No, the dire wolf has not been brought back from extinction“, was our headline.

Colossal’s chief scientist, Beth Shapiro, tried to justify the de-extinction claim on the basis of appearance. “We are using the morphological species concept and saying, if they look like this animal, then they are the animal,” she told New Scientist on 7 April.

But even leaving aside the huge genetic differences, it’s not clear that the cloned grey wolves do resemble the extinct animal. “There is no evidence that the genetically modified animals are phenotypically distinct from the grey wolf and phenotypically resemble the dire wolf,” an expert group on canids from the International Union for Conservation of Nature declared on 18 April.

In a second interview with New Scientist, even Shapiro herself seemed to concede the point. “It’s not possible to bring something back that is identical to a species that used to be alive. Our animals are grey wolves with 20 edits that are cloned,” she said. “And we’ve said that from the very beginning. Colloquially, they’re calling them dire wolves and that makes people angry.”

In response to our story quoting Shapiro, Colossal put out a statement reiterating its claim: “With those edits, we have brought back the dire wolf.”

Outside of those who work for Colossal, however, New Scientist is not aware of any biologists who think the dire wolf has been revived. “To my knowledge, there is no support for calling these transgenic grey wolves dire ones,” says Vincent Lynch at the University at Buffalo, New York. “At least in the circles I’m in, there is unanimous agreement that these claims are unjustified.”

Lynch thinks most non-biologists do believe the claim, though, thanks to ongoing media coverage often repeating it as a fact. He and others worry that the belief that extinct animals can be brought back to life will undermine support for conserving endangered species.

“People have absolutely believed these claims, but it is extremely hard to tell how this will play out in the long term for conservation efforts,” says Herridge.

In July, Colossal claimed it would also bring back the moa, a flightless bird from New Zealand. Critics including Nic Rawlence at the University of Otago, New Zealand, said the best the company would be able to do is create a “Franken-moa” that might look a bit like the extinct bird.

Meanwhile, Rawlence, Lynch, Herridge and other prominent critics of Colossal’s de-extinction efforts found themselves on the receiving end of a mysterious smear campaign that the company says it has no involvement in. Anonymous blog posts and videos attacking their expertise and credentials appeared online. Lynch says this ended after New Scientist reported it on 31 July, but another piece attacking Rawlence appeared on 5 September, while Herridge has seen one more dubious article.

Even Colossal’s critics agree that the company is making significant advances. But Richard Grenyer at the University of Oxford thinks all the talk of de-extinction is a distraction from the bigger issues raised by our growing ability to make extensive changes to animals’ genomes. “We probably need to have another discussion as a society about what we will tolerate and what we won’t,” he says.

“There might be some specific cases where this kind of technology is employed for the genetic rescue of bottleneck populations that might have some conservation value, but it’s always going to be very niche, and very expensive.”