The RNA world: Hypotheses, facts and experimental results

A biochemical world that would have existed before the contemporary DNA-RNA-Protein world, and baptized in 1986 «The RNA World» by Walter Gilbert (Gilbert, 1986), such a world had already been proposed during the preceding decades by Carl Woese, Francis By demonstrating the remarkable diversity of the RNA molecule, Molecular Biology proved these predictions. RNA present in all living cells, performs structural and metabolic functions many of which were unsuspected only a few years ago. A truly modern «RNA world» exists in each cell; it contains RNAs in various forms, short and long fragments, single and double-stranded, endowed with multiple roles (informational, catalytic, that can serve as templates, guides, defense…), certain molecules being even capable of carrying out several of these functions. Are the sources of this RNA world to be found in the bygone living world?