Colossal Biosciences: Returning the Tasmanian Tiger to the Land Down Under

Have you seen the iconic images of the thylacine, an instantly recognizable creature with its distinctively dark stripes and elongated jaw? Commonly known as the Tasmanian tiger, the last known thylacine died in captivity in its native Australia in the 1930s after a long struggle against excessive hunting, habitat destruction, and introduced disease and competition. 

As a local Tasmanian icon, the thylacine has long been the subject of intrigue, with individuals proclaiming sightings of the elusive creature continuing into the late 2010s despite the species being officially listed as extinct in 1986. 

While most have moved past the dream of the thylacine returning to Tasmania — especially following the Australian Museum’s failed attempt at cloning the species in 2005 — modern advancements in gene-editing technology have led companies like Texas-based Colossal Biosciences to believe that the thylacine could be among the first animals to be successfully dubbed “de-extinct.” 

“The thylacine is a great candidate for de-extinction because it only went extinct in 1936 due to human hunting and the ecosystem we are looking to return it to is still intact,” Ben Lamm, Colossal co-founder and CEO, told Discovery. “Furthermore, we have incredible tissue samples and genomes assembled, as well as many additional pelts that are being sequenced for population genomics studies.”

The Turbulent History of the Tasmanian Tiger

Once widespread throughout the Australian island state of Tasmania, an estimated 5,000 thylacines were said to occupy the island before European colonisation. Considered the geographical region Oceania’s only marsupial apex predator, the thylacine was known to hunt marsupials, birds, and small rodents, and controlled the populations of herbivorous species like wallabies and kangaroos.

Following the European settlement of Tasmania in the 1800s, the thylacine became the subject of widespread vitriol when the agricultural industry targeted the species as the source of livestock killings. While retrospectively considered a scapegoat for feral dogs and livestock mismanagement, as the island’s largest carnivore the thylacine became an easy target for concerned farmers. 

Bounties were soon set upon the species, with the Tasmanian government introducing an official bounty system in 1888 offering as much as 1 English pound per adult and 10 shillings for a pup. Between 1830 and 1920, it’s estimated that at least 3,500 thylacines were killed by bounty hunters, with increased competition between wild dogs and the continued establishment of settler farms destroying populations even further.

By the time that the last known shooting of a wild thylacine occurred in 1930, the species had become increasingly difficult to locate, with the last known individual being given to the Hobart Zoo in Tasmania in 1931. With growing concerns about the species’ low numbers, the thylacine was granted protected status in 1936 to no avail, as the thylacine at Hobart Zoo died just 59 days later due to suspected neglect. 

Since Tasmania’s loss of its apex predator nearly 100 years ago, increased populations of invasive predator species have altered the native herbivore populations, leading to ecosystem degradation on the island — an issue with serious implications such as an increase in wildfires and the spread of disease. 

The Tasmanian devil, a close relative of the Tasmanian tiger and another of the island’s iconic predators, is one species that’s been directly impacted by the loss of the thylacine. Suffering from a nearly 85% population decline since the 1990s due to the highly fatal devil facial tumour disease, experts believe that this cancer’s impacts may have been lessened if thylacines were around to cull sick and weak individuals.

Given the thylacine’s critical role in maintaining Tasmania’s unique ecosystems, along with recent reports that Tasmania will face the brunt of the impacts of climate change in Australia, companies like Colossal Biosciences are determined to rewild the species before it’s too late. With the thylacine’s well-preserved samples, mostly intact habitat, and relatively recent extinction, Colossal feels well equipped to bring the animal back Down Under.

Colossal Biosciences’ Tasmanian Task

In 2022, Colossal Biosciences partnered with the University of Melbourne’s newly established Thylacine Integrated Genomic Restoration Research Lab to develop innovative de-extinction techniques aimed at the Tasmanian tiger. 

Led by marsupial evolutionary biologist and Tasmanian tiger expert Andrew Pask, PH.D., TIGRR is heavily focused on using assisted reproductive technology, stem cell biobanking, and genomic sequencing and editing to further marsupial conservation efforts. 

Using the sequenced genome of the thylacine and the stem cells of its closest living relative, the fat-tailed dunnart, Colossal Biosciences and TIGRR plan to leverage gene editing technology to create a marsupial cell line with thylacine-like’ traits. This cell line can then be transferred into a close relative of the thylacine (likely a Tasmanian devil) to create a thylacine embryo that can be extracted and implanted into a surrogate for a 42-day gestation period before fully developing in a pouch.

As Pask explained it to Discovery, “We take living cells from our dunnart and edit their DNA every place where it differs from the thylacine. We are essentially engineering our dunnart cell to become a Tasmanian tiger cell. Then we use standard stem cell and reproductive techniques to turn that cell back into a living animal.”

While a timeline has yet to be announced for the thylacine’s de-extinction, Colossal Biosciences has recently announced the formation of the Tasmania Thylacine Advisory Committee to support the endeavour.

Headed by Derwent Valley Council (Tasmania) Mayor Michelle Dracoulis, this committee will bring together the local government, aboriginal representatives, industry leaders, private landowners, university representation, and the public at large to provide quarterly updates and discussions about the thylacine’s rewilding efforts.

“Culturally, on our island, the thylacine is more than an extinct animal,” Dracoulis said in a press release. “It’s part of our identity, and lives strongly in our folklore and imagination. Bringing back the thylacine is an important step in ensuring biodiversity and safeguarding Tasmania for future generations. Its restoration will contribute to much-needed healing in our land, which has a troubled past but is home to a people that have hopes for a brighter future.”

Given its ecological impacts, Colossal expects that rewilding the thylacine will invigorate local communities with bolstered biodiversity and economic opportunity. Colossal and TIGRR are currently in the third phase of thylacine de-extinction, identifying genomic differences to be edited into the marsupial cell line. With a recent study developing a methodology for extracting RNA from the thylacine, Colossal may be even one step closer to rewilding the extinct species. 

With Australia leading in worldwide extinctions in an era where up to 150 species go extinct per day, regardless of how ambitious de-extinction projects may be, there are no misplaced conservation efforts in the land Down Under. If this project continues on its steady path, who knows — perhaps within our lifetime the Tasmanian tiger will become more than just a photograph.