New Study Brings Scientists Closer to the Origin of RNA
One of the biggest questions in science is how life arose from the chemical soup that existed on early Earth. One theory is that RNA, a close relative of DNA, was the first genetic molecule to arise around 4 billion years ago, but in a primitive form that later evolved into the RNA and DNA molecules that we have in life today. New research shows one way this chain of events might have started.
Today, genetic information is stored in DNA. RNA is created from DNA to put that information into action. RNA can direct the creation of proteins and perform other essential functions of life that DNA can't do. RNA's versatility is one reason that scientists think this polymer came first, with DNA evolving later as a better way to store genetic information for the long haul. But like DNA, RNA also could be a product of evolution, scientists theorize.
Chemists at the Georgia Institute of Technology have shown how molecules that may have been present on early Earth can self-assemble into structures that could represent a starting point of RNA. The spontaneous formation of RNA building blocks is seen as a crucial step in the origin of life, but one that scientists have struggled with for decades.
RNA is perfect for the roles it plays in life today, Hud said, but chemically it's extraordinarily difficult to make. This suggests that RNA evolved from simpler chemical couplings. As life became more chemically complex and enzymes were born, evolutionary pressures would have driven pre-RNA into the more refined modern RNA.
"This study is important in showing a feasible step for how we get the start of an RNA-like molecule, but also how the building blocks of the first RNA-like polymers could have found each other and self-assembled in what would have been a very complex mixture of chemicals," Hud said.
"It is amazing that these nucleosides and bases actually assemble on their own, as life today requires complex enzymes to bring together RNA building blocks and to spatially order them prior to polymerization,"said Brian Cafferty, a graduate student at Georgia Tech and co-author of the study.
SPONTANEOUS SPECIATION
