Molecular complexity favors the evolution of ribopolymers.

We have explored the stability of selected ribo oligomers in water and have determined the physical-chemical conditions in which the key 3-phosphoester bond is more stable when embedded in the polymer than when present in the monomer. In these conditions, the spontaneous formation and the survival of ribo polymers are potentially favored. A narrow pH range was identified in which complex sequences resist degradation markedly more than monotonous ones, thus potentially favoring the evolution of sequence-based genetic information. Given that the founding property of a polymer is to maintain its polymeric form and its sequence information, these findings support the view that the evolution of pregenetic molecular information occurred based on intrinsic properties of nucleic polymers.