The pace of evolution across fitness valleys

Chaitanya Gokhale (1) , Yoh Iwasa (2) , Martin A. Nowak (3) , Arne Traulsen (1)

1 Max Planck Institute for Evolutionary Biology
2 Faculty of Sciences
3 HARVARD - Department of Mathematics [Cambridge]

How fast does a population evolve from one fitness peak to another? We study the dynamics of evolving, asexually reproducing populations in which a certain number of mutations jointly confer a fitness advantage. We consider the time until a population has evolved from one fitness peak to another one with a higher fitness. The order of mutations can either be fixed or random. If the order of mutations is fixed, then the population follows a metaphorical ridge, a single path. If the order of mutations is arbitrary, then there are many ways to evolve to the higher fitness state. We address the time required for fixation in such scenarios and study how it is affected by the order of mutations, the population size, the fitness values and the mutation rate.

Mots clés: Finite populations; Stochastic tunneling; Evolutionary speed

Chaitanya Gokhale, Yoh Iwasa, Martin A. Nowak, Arne Traulsen. The pace of evolution across fitness valleys. Journal of Theoretical Biology, 2009, 259 (3), pp.613. ⟨10.1016/j.jtbi.2009.04.011⟩. ⟨hal-00554604⟩