Natural Bleach in Primordial Soup Helped Evolution of Life, Researchers Say

Hydrogen peroxide-a compound commonly associated with hair bleach- might have kick-started life, researchers say.

Around 3.6 billion years ago, the primordial soup ( the cauldron of chemicals where life is believed to have originated) was just a concoction of chemicals without any living organisms.

For years, researchers have been trying to find how RNA replication in the primordial soup started- a process that helps genetic material produce copies of itself.

"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."

According to RNA World- a hypothetical stage in the evolution of life- RNA was the first molecule that was capable of storing information and undergoing primitive replication. DNA, proteins and other molecules originated later.

Researchers have known that ribonucleic acids formed in hydrothermal vents and began replicating and growing. However, replication requires thermal cycling or a heating and cooling phase to separate and re-join base pair strands, according to The Conversation 

Various theories have been proposed to explain the thermal oscillation. A recent study said that the soup was heated and cooled by physical processes.

For the study, Ball and Professor John Brindley from the University of Leeds in Britain developed computer simulations.

 They found that hydrogen peroxide- by undergoing spontaneous, exothermic reactions- could provide the necessary temperature oscillations to drive RNA replication.

Also, the temperature fluctuations caused by hydrogen peroxide are quick enough to prevent damage to the base-pairs present in RNA.

Natural bleach also heated and cooled the system imperfectly leading to variation in the biomolecules. Researchers say that hydrogen peroxide drove evolution and natural selection.

"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," Ball told the Sydney Morning Herald. "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."

Natural bleach isn't found in large quantities now, which might explain why we don't have newer biological molecules growing in hydrothermal vents.

"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 in a news release.

The study is published in the Journal of the Royal Society Interface.