The first extensive study of Indigenous Australians' DNA dates their origin to more than 50,000 years ago, backing the claim that they are the most ancient continuous civilisation on Earth.

Scientists used the genetic traces of the mysterious early humans that are left in the DNA of modern populations in Papua New Guinea and Australia to recontruct their journey from Africa around 72,000 years ago.

Experts disagree on whether present-day non-African people are descended from explorers who left Africa in a single exodus or a series of distinct waves of travelling migrants.

The new study supports the single migration hypothesis. It indicates that Australian aboriginal and Papuan people both originated from the same out-of Africa migration event some 72,000 years ago, along with ancestors of all other non-African populations alive today.

Tracing the Papuan and Australian groups' progress showed that around 50,000 years ago they reached Sahul - a prehistoric supercontinent that once united New Guinea, Australia and Tasmania before they were separated by rising sea levels.