The Effect of Recombination on the Neutral Evolution of Genetic Robustness.pdf

The Effect of Recombination on the Neutral Evolution of Genetic Robustness Gergely J. Sz¨oll˝osi∗ and Imre Der´enyi† Biological Physics Department, Eotvos University, Budapest ¨ ¨ 8 Abstract 0 0 Conventional population genetics considers the evolution of a limited number of genotypes corresponding 2 r to phenotypes with different fitness. As model phenotypes, in particular RNA secondary structure, have p A become computationally tractable, however, it has become apparent that the context dependent effect of 1 2 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 E P the neutral networks corresponding to all genotypes with the same secondary structure only through neutral . o i mutations can evolve mutational robustness [Nimwegen et al. Neutral evolution of mutational robustness, b - q 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 1 v ensembles of random neutral networks that mutational robustness is significantly enhanced and further 9 7 2 that the magnitude of this enhancement is sensitive to details of the neutral network topology. Through 3 . the simulation of finite populations of genotypes evolving on random neutral networks and a scaled down 4 0 microRNA neutral network, we show that even in finite populations recombinati