The Effect of Recombination on the Neutral Evolution of Genetic Robustness

TL;DR

This paper investigates how recombination influences the evolution of genetic robustness in populations, demonstrating that recombination enhances robustness and affects population distribution on neutral networks.

Contribution

It introduces the role of recombination in increasing mutational robustness within neutral networks, extending previous models to include recombination effects.

Findings

Recombination significantly enhances mutational robustness.

Population concentrates on high-neutrality regions due to recombination.

Effects depend on neutral network topology.

Abstract

Conventional population genetics considers the evolution of a limited number of genotypes corresponding to phenotypes with different fitness. As model phenotypes, in particular RNA secondary structure, have become computationally tractable, however, it has become apparent that the context dependent effect of mutations and the many-to-one nature inherent in these genotype-phenotype maps can have fundamental evolutionary consequences. It has previously been demonstrated that populations of genotypes evolving on the neutral networks corresponding to all genotypes with the same secondary structure only through neutral mutations can evolve mutational robustness [Nimwegen {\it et al.} Neutral evolution of mutational robustness, 1999 PNAS], by concentrating the population on regions of high neutrality. Introducing recombination we demonstrate, through numerically calculating the stationary distribution of an infinite population on ensembles of random neutral networks that mutational robustness is significantly enhanced and further that the magnitude of this enhancement is sensitive to details of the neutral network topology. Through the simulation of finite populations of genotypes evolving on random neutral networks and a scaled down microRNA neutral network, we show that even in finite populations recombination will still act to focus the population on regions of locally high neutrality.