Closing A Loophole In The RNA World Hypothesis

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Closing A Loophole In The RNA World Hypothesis

http://www.medicalnewstoday.com/medicalnews.php?newsid=60891

New scientific research may close a major loophole in the RNA world

hypothesis, the idea that ribonucleic acid -- not the fabled DNA

that makes up genes in people and other animals -- was the key to

life's emergence on Earth 4.6 billion years ago. That hypothesis

states that RNA catalyzed all the biochemical reactions necessary to

produce living organisms. Only later were those self-replicating RNA

units joined by organisms based on DNA, which evolved into more

advanced forms of life.

But how did ribonucleic acid appear? Scientists have shown that

other organic compounds can form spontaneously under conditions

believed to exist on the primordial Earth. The University of

Manchester's D. Sutherland and colleagues point out, however,

that no plausible prebiotic synthesis of ribonucleotides, the

components of RNA, has been reported. His group offers the large

part of such a potential synthesis in an article scheduled for the

Jan. 17 issue of the Journal of the American Chemical Society, a

weekly publication.

The researchers describe a process in which each of the two

components for a ribonucleotide form in different locations on the

primordial Earth. They combine when one evaporates and is delivered

to the location of the second component in rainfall.