The team behind an ambitious attempt to ‘de-extinct’ the Tasmanian tiger claims it has produced a reconstructed thylacine genome that is the “most complete and contiguous ancient genome of any species to date”, — but independent scientists are waiting to see the full data before they get too excited.
The last known Tasmanian tiger, or thylacine, died in captivity at a Hobart zoo in 1936, but the species can’t quite shake claims of potential sightings.
In 2022, American bioscience company Colossal Biosciences announced it had formed a partnership with a research lab at the University of Melbourne to bring the marsupial back, a plan that has received a mixture of responses from the scientific community.
Ahead of an appearance at an event in Sydney on Thursday the team has provided a project update, claiming it has made a series of significant advancements — including having produced a thylacine genome that is “more than 99.9-per-cent accurate”.
Andrew Pask, who leads the Thylacine Integrated Genetic Restoration Research (TIGRR) lab at Melbourne University, said it was a “major leap forwards”.
Andrew Pask says the team has been able to extract RNA from a preserved Tasmanian tiger specimen. (ABC News: Luke Bowden)
“And obviously, it’s that DNA that provides the set of instructions, the blueprint, on how to build a thylacine,” he said.
“So the better that genome is, the better the quality you can get that resource, the better the job you can do of bringing the thylacine back.”
Dr Pask said the team had also been able to extract RNA, which is a far less stable biomolecule and hard to preserve, but a key piece of the puzzle for understanding more about the animal.
The last-known surviving thylacine died in captivity in 1936. (Supplied: NFSA)
He said it largely came down to advancements in technology, and the quality of the DNA that was available — in this instance, coming from the head of a Tasmanian tiger preserved in ethanol at Museums Victoria.
“Because people loved thylacines, even back when they were hunting them to extinction. There’s a lot of these samples in museum collections … we’re fortunate that we have a good back catalogue library of species to go through to find those really good specimens,” he said.
A wait for peer-reviewed science
Parwinder Kaur, founder and director of DNA Australia, who has worked with Colossal previously including in efforts to analyse DNA from the woolly mammoth said it was a notable announcement.
“I’m really, really pleased to see things moving forward, because this is like testing the envelope and pushing the science a little bit further to be able to validate a lot of things which still feels like science fiction,” Associate Professor Kaur said.
She said she was particularly excited by progress in the artificial reproduction space, with the Colossal team announcing they’ve discovered an optimised approach to inducing ovulation in a dunnart, which is the proposed surrogate host for the recreated thylacines.
Colossal said they had been able to take “fertilised single-cell embryos and cultivate them to more than halfway through the pregnancy period”, in an “artificial uterus device”.
Parwinder Kaur says the announcement is exciting, but the evidence should be peer-reviewed. (Image: Supplied)
Associate Professor Kaur said those learnings could have significant applications for a vast number of animals at risk of extinction, down the line.
However, she said she wanted to see the peer-reviewed data that could back it all up, before she got too excited.
“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 said.
“We don’t want to be getting ahead of ourselves.
“If we make the claims but they are not peer-reviewed, and they are not approved and they never come to fruition, then it’s a huge disappointment for the entire community.”
Parwinder Kaur worked with the Colossal team on its woolly mammoth project.
Dr Pask said each of the achievements outlined Colossal would be backed up by peer reviewed studies, which he expected to occur from early next year.
He said Colossal had an ambition to keep the public updated on progress as it happened, but that the studies would contain “all of the data for everybody to interrogate and have a look through.”
De-extinction not achievable, scientist says
Kristofer Helgen, chief scientist at Australian Museums Research, was less optimistic.
He said while he welcomed “that kind of genome coverage” being achieved for an extinct species, and believed it was possible due to the continuing advancements in the field, he also wanted to see announcements coming alongside peer-reviewed studies.
Kristofer Helgen says he welcomes the advancements, but remains unconvinced of the viability of the overall goal. (Supplied)
Professor Helgen said, even if the genome was perfect, it was only one tiny piece of the puzzle.
“What’s really important for people to realise is that it’s not a genetic manual.
“I think any time we learn more about the genomes of any of these extinct species, it’s a win. But I love it mostly for the reason that we can … learn more because we have some more information — not at all because it’s going to allow you to reassemble the animal.”
He said he remained certain there was no chance the Tasmanian tiger could be brought back.
“All that’s being promised is a genetically modified dunnart.”
Andrew Pask says while there’s a long road ahead, significant progress was being made. (ABC News: Patrick Rocco)
Dr Pask disagreed with Professor Helgen’s assessment of what the end result would be, but he didn’t shy away from the fact there was a significant amount of work still to do.
However, he said de-extinction was possible.
“We need to stop focusing on the ‘if’ and shift the narrative to how we can thoughtfully use this new technology to preserve and revive biodiversity in the midst of the sixth mass extinction.”
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