Future of species unpredictable: study

The world is facing a mass extinction event that could be greater than that of the dinosaurs, new research shows.

Macquarie University palaeobiologist Dr John Alroy used fossils to track the fate of major groups of marine animals throughout the earth's history.

He compiled data from nearly 100,000 fossil collections worldwide, tracking the fate of marine animals during extreme extinction events some 250 million years ago.

The findings, published this week in the international journal Science, showed a major extinction event was currently under way that had the potential to be more severe than any others in history.

"Organisms that might have adapted in the past may not be able to this time," Dr Alroy said.

"You may end up with a dramatically altered sea floor because of changes in the dominance of major groups. That is, the extinction occurring now will overturn the balance of the marine groups."

The research shows a combination of human behaviour and climate change could have devastating affects on species across the planet.

"When there's mass extinction all bets are off and anything could happen," Dr Alroy told AAP.

"So what we're basically doing as the human species collectively is we're running this gigantic experiment with nature."

There have been three major mass extinction events throughout history and biologists widely agree the world is currently suffering from another.

The last mass extinction was an estimated 65 million years ago when an asteroid smashed into Mexico and wiped out the dinosaurs, making room for mammals to thrive.

Dr Alroy said a new mass extinction wouldn't be the result of a single horrific event such as an asteroid hitting Earth.

Instead, it would be the result of factors from introduced foreign species, run-offs from fertilisers and pesticides, pollution and deforestation, he said.

Climate change and an accelerated growth in the worldwide population were also playing a part.

But Dr Alroy said the current situation was not yet as bad as the worst mass extinction 250 million years ago, known as Permian-Triassic extinction or The Great Dying.

"It's safe to say that we have not yet lost nearly as much as what was lost during that event but it's also reasonable to say that we could end up losing as much as was lost in that event," he said.

"We're currently playing games with evolution on a epic scale.

"Really, really big mass extinctions happen very, very rarely and they have very important long-term consequences."