New Zealand Tasmanian tiger skin provides DNA from extinct marsupial

By Karoline Tuckey of RNZ

Tasmanian tigers, or thylacines, were a fox-like marsupial that became extinct on the Australian mainland less than 2,000 years ago. Tasmania’s surviving population was wiped out by European settlers who thought they were a threat to their sheep, and the last living thylacine died at a zoo in Hobart in 1936.

New Zealand fur has revealed new information about their coats and provided some surviving DNA.

It was purchased in 1923 by the taxidermist and collector Archibald Robertson of Whanganui.

After Robertson’s death, it was displayed by family friends, who ran the small Kahutara taxidermy gallery near Martinborough, where it was discovered by scientists who discussed the find with Te Papa’s curator, Alan Tennyson.

“It’s one of the most famous extinct animals in the world, and a lot of attention is paid to it even today; they are still investigating how it lived and what happened to it. The focus has never really been diverted from the thylacine, so the new stuff here in New Zealand it’s really exciting, “he said.

“It was quite unexpected, obviously … it had been around New Zealand for many decades, but it hadn’t caught the attention of the scientific community that was working with thylacines globally.

“I had heard about it, some reports came in about it and in 2017 I read a global review of all the specimens, and I was very surprised that that, and the pair of skulls that we have in Te Papa, do not appear in their database. “.

Tennyson wrote to the lead author of the global review to tell him about the specimens here, “and he was very interested.”

“I knew it was a very beautiful skin, but without knowing the global situation with the state that others were in all over the world, it was not clear how important it was, but it seems that it is really one of the best that still exists. preserved anywhere, “Tennyson said.

What scientists learned from Whanganui’s skin

David Thurrowgood, Curator of the Queen Victoria Museum in Tasmania, helped organize the purchase of the fur by the National Museum of Australia. He told ABC that Whanganui’s fur is unique because it offers a special insight into the thylacine’s color and fur structure.

Most thylacine skins were preserved using arsenic or mercury, with methods that destroyed the DNA, but this skin was preserved by a different method that allowed the long DNA fragments to remain intact.

Samples have been taken and compared with DNA stored at the University of Melbourne.

Thurrowgood told ABC that only a few observations of thylacine hair have been made in the past, and that Whanganui’s skin was more vivid than the other faded skins that museums have.

“So I was able to see hair quite differently and there are eight different types of hair in a thylacine.

“The rich chocolate browns in the stripes and the honey colors, to the really beautiful grays on the underside of the animal, indicate how beautiful it would have been,” he said.

“Some of the hairs are hollow, a bit like other species that live in the cold, and they use those thin pockets of air to keep warm and adapt well to the Tasmanian climate.”

What else could the skin offer?

Tennyson says DNA from Whanganui’s skin could provide researchers with more insight.

Studies have already been done on thylacine DNA, but there isn’t much out there, and greater diversity gives more clues.

“Ultimately, there are only a limited number of these extinct animal remains, so it is a very limited group and the number that is being discovered is decreasing, so something like this that was discovered so recently is really exciting, “says Tennyson.

“The science of DNA research has really taken off in the last few decades, so a lot more information can be found using DNA … so it’s great that this clearly has good DNA. That will allow the research team to discover much more about the individual history of this particular animal. “

What else is new and promising in the thylacine discovery?

The thylacine was officially declared extinct in 1986, but unconfirmed sightings are regularly reported in Tasmania. Searches have not been able to find any solid evidence that there might be any surviving population remains.

In 2000, scientists at the Australian Museum announced a project attempting to clone a Tasmanian tiger using genetic material from a cub that had been preserved in alcohol, sparking debates about science and ethics about whether a species could or should be revived. extinct. But the project was scrapped in 2005, because the genetic material was too damaged.

However, in 2017, Australian scientists announced that they had sequenced the puppy’s genome.

Marsupials and wolves are a unique example of convergent evolution, where two very different species become physically similar and fulfill the same niche roles, and that team wanted to compare the genetics of the two species to see if there was any similar code in their. genetics. Flat.

The study showed that there was not, but it unexpectedly showed a strong bottleneck in the genetic diversity of the population somewhere between 70,000 and 120,000 years ago, which likely reflects some kind of environmental stress on the species, such as a change in the weather.

Tennyson says that the more we continue to discover about thylacine, the better we can understand general questions about the evolution and destruction of species.

“I would love for them to be out there, but I’m afraid I have no faith that there are, because they are quite a large animal, and it has been many, many decades since there were confirmed sightings, and a lot of people have been searching.

“It is simply amazing to hear about new specimens of extinct things that are appearing, and of which this one is preserved that they hide in the corners, without a doubt there are many other treasures hidden in small museums around the place that we have not yet found.”

“It is important that we maintain an interest in these extinct animals, because the more we can learn about why they became extinct, it will help us understand current conservation issues and hopefully lead to better conservation outcomes for other species in the future.” .

– RNZ