While thylacines are considered to be a quintessentially Tasmanian animal, the extinct marsupial once roamed the entire country.
Carbon-dating of thylacine fossils shows that the last of the species most likely died out about 3000 years ago on mainland Australia.
Associate Professor Dr Jeremy Austin and PhD student Lauren White from the University of Adelaide believe the cause of this extinction was due to a very contemporary problem – climate change.
The genetics professor explains that their recent assessment of thylacine DNA reveals a sudden change affected thylacine populations throughout the nation.
“From a bone or tooth sample, you can create a phylogenetic tree from DNA, [which] essentially looks like a normal tree,” Dr Austin said.
“In Tasmania, there were lots of very short branches, which tells us the Tasmanian population went through a population crash some time in the last 3000 years.
“We know that thylacines went extinct on the mainland 3000 years ago and the Tasmanian population went through this population crash at about the same time.
“We think the same thing happened on the mainland and in Tasmania, but the Tasmanian thylacines survived.
“We think the only thing that could affect Tasmania and mainland at the same time is a change in climate from a relatively stable one to an unstable one.”
Dr Austin believes the thylacine’s survival in Tasmania could be due to the island’s smaller dingo and human population.
There is other evidence that thylacines existed on the mainland, aside from fossils.
Rock carvings of thylacines can be found from Western Australia to New South Wales.
Tasmanian Aboriginal Land Council chairman Clyde Mansell said thylacines feature prominently in some dreamtime stories from the mainland.
“In the Northern Territory people’s dreaming, the tiger was destroyed by the coming of the dingo on the mainland,” he said.
“But the dingo couldn't get down to Tasmania, so the tiger was protected.”