Shedding new light on the origins of life

20 March 2014

Researchers looking at the origins of life on Earth have come up with a new explanation for how the earliest molecular material was able to replicate in the primordial soup.

They have found that hydrogen peroxide, an ingredient commonly associated with hair bleach, may have been the key to the early replication of RNA - the polymeric molecule that is thought to have existed before cellular life and DNA.

The research sheds new light on how the earliest forms of life developed, and helps explain the mystery of why new forms of life don't emerge on modern Earth.

"The problem of how life originated is enormously complicated," said lead researcher Dr Rowena Ball, from the ANU Mathematical Sciences Institute.

"But we now have one piece of the puzzle that we didn't have before."

More than 3.6 billion years ago there were no living cells and no proteins in the primordial soup on Earth.

Scientists have long believed that cell-free RNA grew in rock pores around hydrothermal vents. But for RNA to replicate, it needed both a heating and cooling phase, which posed questions over the theory.

Dr Ball and Professor John Brindley from the University of Leeds in Britain modelled RNA replication by using hydrogen peroxide, which can undergo rapid temperature cycling and which evidence shows to have been present on the early Earth.

Their detailed simulations found that hydrogen peroxide could provide the kinds of temperature oscillations needed to drive the rapid replication of RNA.

"Our results also may provide an answer to the previously unanswerable question of why life does not emerge from non-living precursors around modern hydrothermal vents on Earth," Dr Ball said.

The findings have been published in the Journal of the Royal Society Interface.