In a groundbreaking development, Colossal Biosciences has announced the birth of three genetically engineered wolf pups, designed to resemble the long-extinct dire wolf. Using CRISPR gene-editing technology, the Texas-based company altered modern grey wolf DNA to mimic physical traits of this prehistoric predator. The pups—named Romulus, Remus, and Khaleesi—are the first of their kind.
The project marks a new step in genetic engineering, combining modern tools with ancient DNA. But experts caution this is not true de-extinction, and many questions remain about the biological and ethical impacts.
CRISPR Technology Used to Engineer Ancient Traits
Colossal’s scientists used DNA from ancient dire wolf fossils, including a tooth from Ohio and a skull fragment from Idaho, to guide their editing. By targeting 20 key genetic sites, they modified traits like jaw structure, fur length, and body size.
The process began by inserting the edited DNA into dog egg cells. These embryos were then implanted into domestic dog surrogates, which carried the pups to term. The three wolves now weigh about 36 kilograms and are expected to reach 63.5 kilograms as adults.
“Our goal was to recreate the look and size of dire wolves using their closest living relatives,” said a lead scientist at Colossal.
According to the company, the pups have long white fur and strong, muscular jaws—features often associated with dire wolves in scientific records.
Scientists Say True De-Extinction Remains Elusive
Despite the buzz, many biologists say this achievement does not represent real de-extinction. Independent researchers stress that cloning an extinct species remains scientifically impossible with current technology.
“You can’t bring back an animal that’s been extinct for 10,000 years with this method,” said Vincent Lynch, a biologist at the University of Buffalo. “These wolves are not clones. They’re just edited versions of modern wolves.”
Nic Rawlence, a paleogeneticist from New Zealand, agreed. He explained that DNA from ancient fossils is too degraded for cloning. Even full genome sequences don’t provide DNA strands long enough to rebuild a complete animal.
“What Colossal made is more of a hybrid,” Rawlence added. “It looks like a dire wolf but doesn’t carry all the traits of one.”
Wolves Won’t Play the Role of True Dire Wolves
Experts also pointed out that the engineered wolves will not learn key survival behaviors like hunting in packs or managing large prey. These skills are often passed down from parents in wild environments.
“You can recreate appearance,” said Lynch, “but you can’t give them the full ecological role.”
Colossal’s team agrees. Matt James, head of animal care at the company, said the animals won’t fill the niche dire wolves once held in North American ecosystems. Instead, they will remain in managed care for observation and future research.
Conservation Through Gene Editing
While de-extinction may still be far off, Colossal is pushing forward with similar efforts. The company is also working on projects involving woolly mammoths and dodos, aiming to restore lost traits in endangered animals through careful DNA modification.
Recently, the firm successfully cloned four red wolves, using genetic material from critically endangered populations in the southeastern United States. The goal is to boost genetic diversity in captive breeding programs.
Ben Lamm, CEO of Colossal, defended the company’s mission:
“We’re not just trying to bring back the past—we’re using technology to protect the future of biodiversity.”
He emphasized that engineered traits can help preserve species that are close to extinction, adding that public opinion is catching up with scientific progress.
Ethical Questions and Government Interest
Though the process is less invasive than traditional cloning, it still raises ethical and logistical concerns. Wildlife ethicist Christopher Preston praised the low-impact method but noted it still involves sedating animals to collect genetic samples.
In late March, Colossal scientists met with U.S. Interior Department officials to discuss future applications. Interior Secretary Doug Burgum called the development “a thrilling new era of scientific wonder” on social media.
However, many researchers continue to warn that technology is not yet ready to fully restore extinct species. They advise focusing on protecting animals currently at risk of extinction.