A study has found that the Tasmanian tiger, also known as the thylacine, was struggling genetically before it was hunted to extinction in the mid-20th century.
Looking at the DNA of the last known thylacine, scientists reported in the journal Nature Ecology and Evolution that the creature likely would have died out even without human contact. The study was led by scientists from the University of Melbourne.
"Even if we hadn't hunted it to extinction, our analysis showed that the thylacine was in very poor [genetic] health," lead researcher Dr Andrew Pask, from the University of Melbourne, told BBC News.
"The population today would be very susceptible to diseases, and would not be very healthy."
Its poor genetic diversity stretched back 70,000 years, possibly as the result of a climatic event. Their numbers declined dramatically tens of thousands of years ago when humans arrived in Australia, and then again as a result of dingoes.
The animal became isolated on Tasmania 10,000 to 13,000 years ago, hence the name. Overhunting ultimately led to its extinction in 1936, but this analysis shows its genetic weakness would have made it more susceptible to disease even if it had survived.
The last known thylacine died on September 7, 1936 at a zoo in Hobart, Australia. This is the first study to look at the complete genome of the species, giving us a rare view into its history.
While much about its behavior is unknown, we do know it was the largest known carnivorous marsupial of modern times. It hunted in groups, and may have included kangaroos and wallabies among its prey.
In fact, the animal appears to have had quite a lot in common genetically with the kangaroo, although it looked more like the Australian dingo. Dr Pask told The Guardian its appearance was “almost a dingo with a pouch”.
“Their similarities are absolutely astounding because they haven’t shared a common ancestor since the Jurassic period, 160 million years ago,” he said.
This story shouldn’t particularly excuse humans of hunting an animal to extinction. But it does seem like this poor animal was doomed regardless – we may have just accelerated the inevitable.
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