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arXiv · 1708.02667

Evolutionary advantage of directional symmetry breaking in self-replicating polymers

Hemachander Subramanian·Robert A. Gatenby
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Abstract

Due to the asymmetric nature of the nucleotides, the extant informational biomolecule, DNA, is constrained to replicate unidirectionally on a template. As a product of molecular evolution that sought to maximize replicative potential, DNA's unidirectional replication poses a mystery since symmetric bidirectional self-replicators obviously would replicate faster than unidirectional self-replicators and hence would have been evolutionarily more successful. Here we carefully examine the physico-chemical requirements for evolutionarily successful primordial self-replicators and theoretically show that at low monomer concentrations that possibly prevailed in the primordial oceans, asymmetric unidirectional self-replicators would have an evolutionary advantage over bidirectional self-replicators. The competing requirements of low and high kinetic barriers for formation and long lifetime of inter-strand bonds respectively are simultaneously satisfied through asymmetric kinetic influence of inter-strand bonds, resulting in evolutionarily successful unidirectional self-replicators.

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Hemachander Subramanian, Robert A. Gatenby. 2017-08-08. Evolutionary advantage of directional symmetry breaking in self-replicating polymers. https://arxiv.org/abs/1708.02667

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