Koala population crashed 100,000 years ago due to climate change, DNA study finds

A new DNA study has changed how scientists understand the history of koalas. Researchers found that the species nearly disappeared around 100,000 years ago, long before humans reached Australia. The study analyzed hundreds of koala genomes and calculated the mutation rate for the first time. This allowed scientists to trace the population history of the marsupial. They discovered that every koala alive today is descended from a small group that survived extreme climate shifts. This group later repopulated eastern Australia. The findings suggest that koalas have faced major environmental challenges in the past and adapted. The research gives new insight into how koalas might respond to future climate change. It also highlights the importance of protecting their habitats. The study was conducted by scientists at several universities and research institutions. They sequenced the genomes of koalas from different regions in Australia. By comparing genetic differences, they estimated when the population size changed. The data showed a sharp drop around 100,000 years ago, followed by a slow recovery. This was likely caused by droughts and other climate changes during the last ice age. The koala is now listed as vulnerable in parts of Australia. Understanding its past can help plan conservation efforts.