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PDF 445 KB
Pages 856-863
First published 30 July 2014

Pre-template Metabolic Replicators: Genotype-Phenotype Decoupling as a Route to Evolvability

William Hurndall, Richard Watson and Markus Brede

Abstract (Excerpt)

The RNA World is widely heralded as the leading candidate for a template first vision of the origin of life, yet doubts as to the plausibility of the natural formation of RNA with catalytic function have led to revived interest in the metabolism first paradigm. Recent studies of the evolvability of reflexively autocatalytic sets of polymers have also revealed the nature of limited heredity in compartmentalised reaction networks. In the algorithmic sense, the lack of a meaningful distinction between data storage and functional expression results in a protocell heredity-fitness dichotomy which gives an intrinsic selective advantage to those protocells with limited heredity. An idealised model is used explore a minimal set of dynamical requirements necessary to weaken the dichotomy. This is achieved by explicitly modelling a protocell as an outer compartment 'phenotype,' heritable only indirectly, in which competitive exponential growth may occur without compromising the heritability of previously discounted non-competitive growth autocatalysts in an inner sub-compartment, 'genotype.' Results show that heritable variation can be achieved under simulations of natural selection in populations of such metabolic replicators.