Climate change a major contributor to extinction of the Tasmanian tiger, scientists say
NEW RESEARCH from the University of Adelaide has revealed the possible reason behind the extinction of the Tasmanian tiger (Thylacine) from mainland Australia thousands of years ago. And it wasn’t due to dingoes or any human activity as was previously believed.
Instead, scientists say that the rapid decline of the Tasmanian tiger on mainland Australia, which occurred at the same time populations of the animal in Tasmania crashed, can be put down to climate change. “Specifically the onset of unstable climate associated with El Nino-Southern Oscillation around 4000 years ago,” head researcher, Jeremy Austin told Australian Geographic.
“We can only speculate but the unstable climate could have affected the number of prey available or altered the habitat in which thylacines lived – both of these things may have been sufficient to start a population crash,” he said.
The authors of the paper, published today in the Journal of Biogeography, came to their conclusion by analysing DNA from fossil bones and museum specimens, including bones and skins from 51 thylacines from across southern Australia— the largest pool of DNA to ever be tested.
“We used one type of DNA called mitochondrial DNA to look at the overall genetic diversity within thylacine populations, understand how Tasmanian and mainland populations were related to each other, and to reconstruct how the population size had changed over time,” Jeremy explained.
He added that it’s possible that the thylacine populations in Tasmania were on the increase prior to the arrival of Europeans. “Perhaps this makes their extinction in 1936 even more depressing— a species that had managed to survive one “near death” experience, gets wiped out 3000 years later.”
Jeremy said that in order to get a better picture of how and when the populations changed in size, fuirther analysis of the DNA will be required. “Can we identify exactly when the mainland population went into decline and how small was the population decline in Tasmania?” are among the important questions to be answered in the future.
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