Even de-extinction advocates say that Colossal Biosciences’ claims are misleading
Are dire wolves back? Many outlets, among them the New Yorker and Time magazine, reported recently that US biotechnology company Colossal Biosciences had brought the giant canines back from extinction. And almost immediately, scientists and conservationists began expressing outrage at Colossal’s claim. “It’s not a dire wolf. It’s misleading to call it that,” says Vincent Lynch, an evolutionary biologist at the University at Buffalo. “I can't explain how pissed off it made me, because they're still saying this stuff, and they know it to not be true.” David Shiffman, an environmental scientist and independent policy consultant, agrees. “This is not a dire wolf by any reasonable definition of a dire wolf,” he says. “This is a gray wolf that has had a tiny fraction of its genes modified to look more like what they think a dire wolf looked like. That means these animals are still gray wolves.” Dire wolves once roamed North America before going extinct roughly 10,000 years ago. They were about the same size as the largest of modern gray wolves but are genetically more closely related to jackals. The species was popularized by HBO's Game of Thrones, which used wolf-dog hybrids during filming. Colossal’s dire wolf reveal wasn’t the first time the company has made headlines. It was founded by George Church and Ben Lamm in 2021. Lamm told C&EN in an interview earlier this year that Colossal was “the world's first de-extinction company.” The founders have been open about wanting to bring back the woolly mammoth and only a month ago reported that they had engineered mammoth traits into mice. At the time of that announcement, the three puppies from their dire wolf project had already been born, kept secret in a 2,000-acre secure preserve in an undisclosed location in the US. Only those with privileged information knew of the wolves’ existence. That is until the New Yorker broke embargo and published its story, “The Dire Wolf Is Back,” and the media bubble burst, according to Evelyn Brister, a conservation scientist and philosopher at the Rochester Institute of Technology who was told about the embargo by Colossal. Time magazine’s cover story quickly followed, along with pieces from Wired and other outlets that were given access to the wolves and Colossal before the planned announcement. Those articles describe how Colossal took gray wolves and made genetic edits in 14 of their genes based on ancient DNA sequencing of dire wolf fossils to give the puppies the appearance of dire wolves. Those stories also repeat a claim made in Colossal’s own press materials that this was the first successful de-extinction of a species in human history. But Colossal was not prepared for its news to get out so early. The firm’s website hadn’t yet been updated. Colossal has also said privately that it planned to release a preprint scientific paper to coincide with media coverage but that it wasn’t ready when the news broke, according to Brister. That preprint was eventually released on April 11, 2025 (bioRxiv, 2025, DOI: 10.1101/2025.04.09.647074) People are now having a very public conversation about these dire wolves and what de-extinction is or if it’s even possible at all. But regardless of where people fall in the de-extinction debate, one thing is very clear: this conversation never should have come about the way it has. ‘De-extinction is not resurrection’ “The announcement of the dire wolves has broken with the tradition of everything else that Colossal and others have been doing in this field,” says Ben Novak, lead scientist at the US de-extinction nonprofit Revive & Restore. Novak was completely unaware of Colossal’s dire wolf project until the news came out. And he says that transparency needs to be a core tenet of de-extinction research. “You don't announce a de-extinct animal when it's 6 months old. You announce a project when you start it. It doesn't really feel good to me,” Novak says, referring to the way Colossal announced the work. Novak has been working in the de-extinction field for over 13 years, primarily on a project to revive the extinct passenger pigeon, at one point even working under Colossal chief science officer Beth Shapiro years before Colossal’s launch. He published a paper in 2018 that helped define what de-extinction is for the scientific community, though that definition isn’t universally agreed upon (Genes, DOI: 10.3390/genes9110548). The standard definition for de-extinction is given by the International Union for Conservation of Nature (IUCN), the organization that publishes the globally recognized Red List of Threatened Species. Novak’s definition is an extension of IUCN’s. And it takes into consideration that when no living tissue from an extinct species remains, that lineage is gone for good. “De-extinction is not resurrection,” Novak says. According to Novak, de-extinction is taking a relative of the extinct species and modifying it so that it embodies the characteristics of the original species, which includes looks but also an organism's behavior and role in an ecological setting. “But even then, it's never the original animal,” he says. “That animal is extinct, that lineage is extinct, but it's a new entity that has some genetic legacy. It's a hybrid.” So in Novak’s eyes, the Colossal dire wolf does not count as the world’s first de-extinction because those wolves have only a slight physiological and genetic resemblance to the extinct species, and we still don’t know anything about how those wolves act in an ecological context. “When I look at a white wolf on the cover of Time magazine, it's just an arctic wolf. We have white wolves. It's no bigger, it's no different looking,” he says. Brister is another proponent of de-extinction efforts. She’s enthusiastic about the work Colossal has done but also says calling the firm’s work de-extinction is going too far. “I think they've done something really important. And it is a step toward de-extinction. But de-extinction is a process,” she says. “It sounds like the dire wolf is kind of a publicity stunt. Partly because we understand canine genetics well and also because of Game of Thrones.” The difference in opinion between de-extinction proponents, like Novak and Brister, and critics often seems to come down to semantics. Sean Stankowski, an evolutionary biologist at the University of Sussex, echoes a lot of Novak’s points about what makes something a species. But he’s much more conservative when it comes to the language used to describe this work. “I think to just so blatantly state that they have successfully resurrected a species is, to me, quite a crude and slightly careless thing to say.” Much like Novak, Stankowski says that while the precise definition of a species is fluid, it’s made up of many components, including genetics, behavior, and ecological role. Which is why Stankowski thinks that even if the company had a 100% pure dire wolf genome, putting it into a wolf embryo and raising it in a modern environment isn't resurrecting the species as it once was. “I'm still not completely convinced that's an accurate way to describe what has been done.” Colossal did not respond to two interview requests from C&EN about the details of their dire wolf project. The value of good press Colossal Biosciences is a for-profit biotech company with a remarkable $10 billion dollar valuation, as reported following its series C funding announcement earlier this year. That’s pretty unusual given that conservation work doesn’t sell a product to anyone. Lamm himself told C&EN in February that Colossal makes money for its investors by spinning off the tech it develops into other companies that do have a more defined product to sell. But to keep the venture capital machine going, the company relies on getting massive media coverage. Brister says Shapiro and other folks at Colossal are usually more restrained with their claims in conversation with other scientists and the media. They use terms like “functional de-extinction" to imply they aren’t trying to resurrect the exact animal that went extinct but to create versions that are more like modern replicas. That restraint was true of Lamm and Shapiro’s conversation with C&EN. But Colossal’s dire wolf press release takes a different tack. It’s titled, “Colossal Announces World’s First De-Extinction: Birth of Dire Wolves,” and features a slideshow of the genetically engineered wolf pups alongside the scientific name for the extinct dire wolves, Aenocyon dirus, implying their creation and the long extinct species are one and the same. None of these claims were evaluated by scientists outside the company’s sphere of influence before they were made, according to Novak. Even if a scientific article preprint was made available at the same time as the announcement, that article would not have gone through peer review. And if it had, it’s possible these statements would not have been so bold. But Colossal’s extravagant claims have given the firm some great press. And even though a second wave of more critical reporting on its dire wolf project is being published at many outlets, Colossal continues to dominate the conservation conversation. And that may be a great thing for investors, but it's poor scientific practice. Much of the work does hold some scientific value, because genome editing can help us learn about the genetic basis of traits, according to many sources. “I guess all we're really doing is critiquing the angle, not necessarily the work itself,” Stankowski says. Buried in all the media coverage is an announcement that the company has also successfully cloned four endangered red wolves. “I think that’s the big news,” Brister says. “That’s not just a publicity stunt.” The consequences of overhype Yet it’s the dire wolf story that leads. Lamm himself brought word of Colossal’s supposed successful de-extinction to US interior secretary Doug Burgum, according to reporting in The Munich Eye. Burgum then posted his thoughts on X, saying that he’s “excited about the potential of ‘de-extinction’ technology” and that it can “serve as a bedrock for modern species conservation.” The mission of the U.S. Fish and Wildlife Service is to work with others to “conserve, protect, and enhance fish, wildlife, plants, and their habitats for the continuing benefit of the American people.” The Department of the Interior is excited about the potential of… — Secretary Doug Burgum (@SecretaryBurgum) April 7, 2025 That’s got some people worried that Colossal’s de-extinction work is actively doing more harm than good. Shiffman, responding to the post over email, tells C&EN that “politicians now want to use pseudoscience as a justification to undo hard-won and evidence-based protections for animals that really need it.” Mike Senatore, senior vice president of conservation programs at Defenders of Wildlife, released a statement in response to Burgum’s post, saying, “Developing genetic technology cannot be viewed as the solution to human caused extinction, especially not when this administration is seeking to actively destroy the habitats and legal protections imperiled species need.” Brister doesn’t see Burgum’s statement in quite the same light. “These technologies and the new scientific knowledge unlocked by genomics can work in concert with the core tool of conservation—which necessarily remains habitat preservation. The Secretary’s message is one that people across the political spectrum can agree with,” she tells C&EN via email. However, Brister does add that “innovation and regulation are conjoined, rather than being in opposition to each other.”