Product inhibition can accelerate evolution

Abstract

Molecular replicators studied in-vitro exhibit product inhibition, typically caused by the hybridization of products into complexes that are not able to replicate. As a result, the replication rate and the selection pressure is reduced, potentially allowing the "survival of everyone". Here, we introduce a stochastic evolution model of replicating and hybridizing RNA strands to study the effect of product inhibition on evolution. We found that hybridization, though reducing the efficiency of replication, can increase the rate of evolution, measured as fitness gain within a period of time. The positive effect has been observed for a mutation error smaller than half of the error threshold. In this situation, frequency-dependent competition causes an increased diversity that spreads not only within a neutral network but also over various neutral networks through a dynamical modulation of the fitness landscape, resulting in a more effective search for better replicators. The underlying model is inspired by RNA virus replication and the RNA world hypothesis. Further investigations are needed to validate the actual effect of accelerated evolution through product inhibition in those systems.