Ancient humans not to blame for extinction

·1-min read

Researchers have debunked the popular theory that ancient humans were responsible for mass extinctions on islands.

Archaeologists and palaeontologists from the Australian National University and Griffith University called together researchers from around the world to examine records spanning 2.6 million years, comparing when humans arrived to when species became extinct.

They found there was little overlap between the two events, up until the last thousand years.

"It doesn't fit well with the usual blitzkrieg overkill impact expectation of human arrival," ANU Professor Sue O'Connor told AAP.

For example, on the islands of Timor and Sulawesi, she could not find any ancient extinctions that could be put down to human impact.

On Timor, Prof O'Connor found evidence of giant rats weighing up to six kilograms, existing well after humans inhabited the island, even though they were a good source of food.

"People had a very light footprint. We shouldn't see extinctions as inevitable," she said.

"But dead as a dodo has gone into global colloquial speech."

Lead researcher Associate Professor Julien Louys from Griffith University said there were very few cases where it could be demonstrated mass extinction had shortly followed island colonisation.

"We show that the successful colonisation of islands does not necessarily require wholesale destruction of ecosystems," Associate Professor Louys said.

The research team also found examples of humans being forced to abandon islands, and of human ancestors becoming extinct.

"The unique ecological conditions that drive island extinctions definitely didn't spare humans either," said Prof O'Connor.

She said in the recent past, island extinctions had predominantly been driven by forest clearing.

The research is being published in Proceedings of National Academy of Sciences.