2. The Curious Extinction Of The Tasmanian Tiger
The last known thylacine, also known as the Tasmanian tiger, died in captivity in 1936. Since then, thousands of people reported unverified sightings, but with no confirmed records, the animal was declared officially extinct 50 years later. While the continued existence of the thylacine is still up in the air, researchers believe they have solved another mystery surrounding the animal: why it survived on the island of Tasmania when it died out in mainland Australia thousands of years ago.
One hypothesis claimed a disease wrecked havoc on the mainland population. Another said the thylacine went extinct due to its competition with the dingo, an animal not found on Tasmania. However, researchers at the University of Adelaide argue that it was climate change—specifically drought caused by the El Niño weather pattern—which resulted in the mainland extinction.
Scientists at the Australian Center for Ancient DNA sequenced 51 new DNA genomes from thylacine fossils. Their findings showed that Tasmanian tiger populations in Southern Australia split into western and eastern divisions approximately 25,000 years ago. They also showed that the drought had an adverse effect on thylacine numbers in Tasmania, but the higher rainfall offered the island a degree of protection from the warm weather. Therefore, the animal population was able to bounce back before Europeans arrived in the 18th century.