Chemical evolution of RNA on the early Earth
The RNA world hypothesis suggests RNA was the original genetic polymer that arrived spontaneously through chemical mechanisms operating on the early Earth. However, model reaction networks for understanding chemical evolution of RNA are few and far between. In my talk, a rapidly evolving reaction network starting from hydrogen cyanide and powered by gamma radiolysis will be discussed. A variety compounds necessary for ribonucleotide synthesis, namely, cyanamide, the simple sugars glycolaldehyde and glyceraldehyde, as well as 2-aminooxazole are produced all in one-pot. Cyanogen chloride, which was also observed in this radiolytic network, was found to activate RNA monomers for nonenzymatic template-directed RNA polymerization. Such a reaction network has the potential to serve as a model for better understanding and engineering chemical evolution of complex mixtures that could have happened on the early Earth.