De-extinction was big news in 2025 – but didn't live up to the hype
Biologists poured cold water on Colossal Biosciences’ claim to have brought the dire wolf back from extinction, and some worry the overblown headlines will undermine conservation work
Colossal’s so-called dire wolf
Colossal Biosciences
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,” on 18 April.
