The discovery, which is published in The Journal of the Royal Society Interface, provides a convincing answer to a long standing problem in evolutionary science, applied mathematician Rowena Ball said.

She said it may explain why new life does not spring from non-living substances on Earth today.

The Australian National University academic said about 3.7 billion years ago, when there was no life on Earth, simple molecules called RNA existed around hydrothermal vents, cracks in the Earth's surface where heated water spills out.

Dr Ball said most scientists believe DNA evolved from RNA, but until recently no-one had been able to explain how that process began because RNA needs to undergo a process of frequent heating and cooling in order to replicate itself.

With her collaborator John Brindley of the University of Leeds, Dr Ball hypothesised that hydrogen peroxide, a natural form of the bleach now commonly found in hair dye which is thought to have been abundant in those early times, could be the missing piece of the puzzle.

The scientists' computer modelling showed not only that bleach heated and cooled RNA at the right rate to allow it to replicate, it did so imperfectly, beginning to create variation among the molecules and allowing natural selection and evolution to take place.

"The presence of the hydrogen peroxide can damage the occasional base along the chain, which will mean there will be an occasional error when it replicates, you're getting variation," she said.

"If that error makes it less fit in that primordial soup then it will die out, but some of those errors are going to make it fitter as its environment changes."

Dr Ball said the natural bleach no longer exists in large quantities in the modern world, which explains why new life is not emerging from the hydrothermal vents still found under the sea.

But Jupiter's moon Europa does have large quantities of the substance, she said, and it is thought to have once occurred on Mars, which suggests the planetary bodies evolved their own RNA worlds.

The researchers now plan to do some real life modelling of the research, recreating the early origins life in a laboratory.

Dr Ball said it was exciting to have been able to fill in a small piece of the puzzle of how life came to be on Earth.

"It's also quite a coup for interdisciplinary research, because that insight could have not have been made by someone sitting completely within the molecular biology box, it could only have been made by this cross-disciplinary breakthough," she said.