A long-held and popular theory of the precursor to cellular life could be turned upside down, as researchers have claimed in a new study that RNA and DNA may have originally existed together.
The findings, in addition to furthering theories on the origins of life, clash with a widely accepted hypothesis called ‘RNA World’ which posits that cellular lifeforms as we know them developed first from RNA.
The breakthrough study has been published in the journal Nature Chemistry.
‘These new findings suggest that it may not be reasonable for chemists to be so heavily guided by the RNA World hypothesis in investigating the origins of life on Earth,’ said co-principal investigator Ramanarayanan Krishnamurthy, PhD, associate professor of chemistry at Scripps Research.
In the RNA World theory, proposed first in 1968, the molecule acted as the first precursor to cellular life, later evolving into DNA through its interaction with enzymes.
In a new theory, however, researchers have identified a compound present during life’s origin called thiouridine
They believe that, through a few plausible chemical reactions, thiouridine could have been converted into either DNA or RNA.