Tasmanian tigers were in poor genetic health tens of thousands of years before humans came along and hunted them to extinction, a new DNA study of the iconic Australian marsupial shows.
The work also identified where the carnivore sits on its family tree and could help safeguard another beleaguered Apple Isle icon: the Tasmanian devil.
To read the genetic history of the Tasmanian tiger or thylacine (Thylacinus cynocephalus), biologists extracted and analysed DNA from a pup that’s been preserved for more than a century.
The genome, reported in Nature Ecology and Evolution today, is one of the most complete sets of DNA of any extinct animal.
….Analysis of the genome showed that even before humans arrived in Australia, there was very little genetic variation between individual thylacines.
Genetic diversity plays an important role in a species’ survival.
The more different types of genes in a population, the more likely some animals will make it through if their environment drastically changes.
In the case of the thylacine, mathematical modelling traced a genetic bottleneck back 70,000 to 120,000 years ago, which coincided with an ice age.
Rising seas cut Tasmania off from the mainland around 14,000 years ago, meaning the local thylacine population was always low in genetic diversity.
“They were actually in pretty bad genetic shape and it wasn’t because of their isolation on Tasmania. It was a longer-term decline in their history,” Dr Pask said.