The RNA World and Its Evolution

This paper develops Belozersky’s early idea of the precedence of RNA in the origin of life on the Earth. Based on the current knowledge of the functional omnipotence of RNA, three new mechanisms are considered that could be critical for the origin and evolution of the ancient RNA world: (1) the reaction of spontaneous transesterification of polyribonucleotides in aqueous media, which has been recently discovered by A.B. Chetverin and colleagues and could result in elongation of short initial oligoribonucleotides and generate sequence variants for further selection; (2) compartmentation of functional RNA ensembles in the form of mixed molecular colonies on moist mineral surfaces, in the absence of membranes and other envelopes; and (3) systematic exponential enrichment of an RNA population with “ functionally the best” molecules due to alternating dissolution of the colonies upon flooding and formation of new colonies upon drying in ancient pools (“primordial natural SELEX”).__________Translated from Molekulyarnaya Biologiya, Vol. 39, No. 4, 2005, pp. 550–556.Original Russian Text Copyright © 2005 by Spirin.