110-year-old pickled Tasmanian tiger skull provides clues to resurrect species

In a recent achievement, scientists have successfully assembled the most complete Tasmanian tiger genome to date. These findings could play a major role in potentially de-extincting the species.

The reconstructed genome, which is over 99.9% accurate, was developed from a 110-year-old preserved, pickled head of a thylacine, commonly known as the Tasmanian tiger, preserved in ethanol.

“Bringing extinct animals back from the dead is no longer the realm of science fiction but is fast becoming a scientific reality,” says Andrew Pask, head of the University of Melbourne’s Thylacine Integrated Genetic Restoration Research (TIGRR) Lab, who has been at the forefront of these efforts since 2022.

Efforts to de-extinct the thylacine

The meticulously reconstructed DNA, combined with RNA fragments (a much less stable molecule than DNA), offers unprecedented insights into the biology of the thylacine, which went extinct in 1936.

The RNA fragments allow researchers to understand which genes were active in the animal’s tissues, shedding light on its sensory capabilities, such as taste and smell, and even brain function.

The thylacine, a carnivorous marsupial and apex predator, played a crucial role in Tasmania’s ecosystem before human interference led to its extinction. Efforts to bring the species back to life have gained momentum, thanks to breakthroughs in genetic science.

Andrew Pask and his team, in collaboration with Colossal Biosciences, aim to revive the thylacine and advance conservation technologies for marsupials.

“If we look at the modern-day habitat in Tasmania, it has remained relatively unchanged. This means it provides the perfect environment to re-introduce the thylacine, enabling it to reoccupy its niche,” explains Pask.

The assembled genome is similar in size to that of a human, containing 3 billion base pairs of nucleotides. Although there are still 45 gaps in the DNA sequence, scientists are optimistic that further sequencing will close these in the coming months.

Pask emphasized the importance of the genome, stating that having such a high-quality blueprint will significantly accelerate efforts to revive the species. While it might take time, this achievement brings de-extinction closer than ever before.

“These technologies will, for example, improve the breeding capacity of critically endangered species in captive populations—such as the closely related Tasmanian devils being bred to help fight against their extinction from the devil facial tumor disease,” he said .

Scientific skepticism around de-extinction

While there is no doubt that the near-complete reconstruction of the genome of an extinct species is nothing short of incredible, some scientists believe that ideas and claims of true, genuine de-extinction must be taken with a pinch of salt.

Independent researchers, such as Professor Kristofer Helgen of Australian Museums Research, acknowledge the significance of genome reconstruction but emphasize that this is only a small part of a much larger puzzle.

Helgen stressed that a genome is not a simple manual for bringing back extinct species. Many complex biological processes must be understood and replicated before a living thylacine can be produced.

Others, like Parwinder Kaur, founder and director of DNA Australia, echoed this sentiment, calling for peer-reviewed data to back up the claims. While acknowledging the difficulty of such a feat and praising the team’s accomplishments, Kaur urged caution.

“Working in this space, we know how difficult it is to get things together and big kudos to everyone involved here, but it would be lovely to release these claims, following the data,” Professor Kaur told ABC . “We don’t want to be getting ahead of ourselves.”

The future of de-extinction

As we inch closer to de-extincting species like the thylacine (and even the woolly mammoth ), the broader implications are becoming clear. The success of this project could pave the way for future efforts to restore biodiversity and reverse some of the damage done by human-caused extinctions.

The reconstruction of the thylacine genome constitutes a major advancement in genetic research and conservation technology.

The research has considerably furthered and complexified the conversation around humanity’s role (which some might deem ‘interference’) in restoring life, especially one that has gone extinct due to direct human contact.

Whether the thylacine will one day roam Tasmania again is a question for the future, and a loaded, complex one at that, but what cannot be denied is that the journey toward that possibility is real and is advancing genetic science in unprecedented ways.