The RNA world: Conditions for prebiotic synthesis



[1] An overview of proposed steps in the synthesis of RNA from the prebiotic atmosphere and Earth is given, along with some suggestions designed to increase the plausibility of the process. It is assumed that the atmosphere was “slightly reducing,” consisting of nitrogen, carbon dioxide, water and traces of other gases, and that the important source of energy fueling the process is solar ultraviolet radiation. The products HCHO and HCN begin the progress of chemical evolution toward RNA. The traditional approach of a “reaction soup” in the oceans, with its built-in problem of hydrolysis of the products, is abandoned in favor of flow through a solid earth chromatographic adsorption–type reactor. This may be vertical through the surface of solid earth or parallel to it, as in paper chromatography. It is shown that the entire process, on through polymerization of RNA, can be regarded as photochemically driven.