In a quiet corner of a Melbourne museum, researchers stumbled upon an unexpected biological treasure. It may hold the key to resurrecting one of the world’s most iconic extinct species: the Tasmanian tiger, also known as the thylacine. Preserved in an unassuming bucket, the head of a thylacine — skinned and soaking in ethanol for over a century — had quietly awaited its moment to make history.
“We found it in the back of a cupboard,” said Professor Andrew Pask, head of the thylacine integrated genetic restoration research (Tigrr) lab at the University of Melbourne. “It was pretty putrid, a completely gruesome sight. People had chopped large chunks off it.”
But within that mutilated head lay something extraordinary — preserved long RNA molecules, something that scientists had all but given up hope of ever finding for the Tasmanian Tiger. They had found the material that might one day bring the Tasmanian tiger back to life.
A Lost Predator, Found in the Lab
The thylacine (Thylacinus cynocephalus) once ruled as Australia’s apex predator. It was a carnivorous marsupial that roamed the continent for millennia. But by 1936, after decades of persecution by humans, the last known thylacine died in a zoo. The species was declared extinct soon after.
Now, scientists are pushing the boundaries of what we know about genetics in an ambitious effort to bring the thylacine back to life. The effort is led by Colossal Biosciences, a Texas-based biotech firm that has already set its sights on resurrecting the woolly mammoth and the dodo. Their ultimate dream is to reverse extinction.
The preserved head in the Melbourne Museum has propelled this dream forward in ways few could have imagined. Researchers were able to recover not just DNA, but also RNA molecules. Essentially, they had found the genetic readout of an animal’s biology in life.
“This was the miracle,” Pask told The Guardian. “It blew my mind.”
RNA, unlike DNA, doesn’t last long at all. It’s fragile and breaks down quickly after an animal dies. But here it was, intact. It allowed scientists to piece together how the thylacine’s genes functioned in different tissues: how it saw, smelled, and tasted the world around it. They were glimpsing not just the genetic structure of an extinct animal, but how it might have experienced life itself.
Building a Blueprint for De-Extinction
With the help of this pickled head, Colossal Biosciences has assembled what they claim is the most complete thylacine genome ever produced — just 45 gaps left in a sequence that contains some 3 billion pieces of information. It’s an “incredible scientific leap,” according to Colossal’s co-founder, Ben Lamm, that puts the company within reach of its goal.
Lamm’s company, which has raised $235 million and employs over 150 scientists worldwide, is pursuing de-extinction with an audacity that has captivated the imagination and stirred debate. Using cutting-edge genetic engineering, the team plans to take cells from a living relative of the thylacine, a small marsupial called the fat-tailed dunnart, and edit its DNA to match that of the extinct predator.
The modified genetic material would then be implanted into dunnart embryos, with a dunnart female acting as a surrogate. For Pask and his colleagues, the techniques they’re developing — from assisted reproductive technologies to an artificial uterus capable of supporting marsupial embryos — could have profound implications for conservation.
Previously, in 2017, Pask and colleagues took samples from a preserved young thylacine pup and used them to make a full genetic map of the thylacine. This blueprint revealed that the thylacine had extremely low genetic diversity. Long before its extinction, the species was already struggling to adapt to environmental challenges and disease. This mirrors the plight of the Tasmanian Devil, which is currently facing its own genetic bottleneck due to its isolation in Tasmania for over 10,000 years.
A Thylacine, But Not Quite
This work also revealed some pretty incredible things. The thylacine’s skull shape closely resembles that of the red fox and gray wolf, despite the fact that these species have not shared a common ancestor since the Jurassic period. Despite its appearance, the thylacine has nothing to do with the family that gave us dogs. Instead, this is a compelling case of convergent evolution, where unrelated species develop similar traits in response to comparable environmental pressures.
The researchers have already made 300 genetic edits to dunnart cells cultured in a petri dish, Pask revealed — and those are just the small changes so far. The plan is to replace thousands of genetic sequences in these cells with thylacine DNA. Effectively they would transform the dunnart into a kind of living proxy for its ancient cousin.
“Most ancient samples preserve DNA fragments that are on the order of tens of bases long — hundreds if we are lucky,” Pask told New Scientist. “The sample we were able to access was so well preserved that we could recover fragments of DNA that were thousands of bases long.”
Still, the road ahead is long and fraught with challenges. Even if scientists manage to grow a thylacine embryo in a laboratory, what emerges won’t be an exact replica of the predator that once prowled Tasmania’s forests.
“We will probably get some thylacine-like animal,” admitted Euan Ritchie, an ecologist at Deakin University, “but they won’t actually be thylacines.”
The animal they create, Park says, may look the part — complete with the signature stripes across its back — but it won’t be an exact genetic match. And even if it were, the ecological landscape has changed since the thylacine’s extinction. “How will they behave in the wild?” Ritchie asks. “We have no idea because there are no living thylacines left to teach them.”
What’s at Stake?
The thylacine’s disappearance left a gaping hole in its ecosystem, and no one knows what role a resurrected version of the species would play in the modern world. Would it behave like its long-dead ancestors? Could it survive? For the scientists involved, those questions may remain unanswered for years to come — if ever.
The thylacine’s return, if it happens, will force us to grapple with some of the most profound ethical questions of our time. Why bring back an extinct species when so many living animals are on the brink? Is this the best use of scientific resources? And even if we can bring them back, should we?
These are not idle questions. This animal was hunted to extinction by humans and — if the science allows it — there are solid arguments to make that we also have a responsibility to see the damage undone.
Ben Lamm, for one, is undeterred. “We are pushing as fast as possible to create the science necessary to make extinction a thing of the past,” he said.
In a few years, we may witness the birth of a “thylacine-like” creature, born of cutting-edge genetic science. Whether it will run wild through Tasmania’s forests as its ancestors once did, or merely serve as a symbol of what science can achieve, remains to be seen.
