Deterministic and stochastic regimes of asexual evolution on rugged fitness landscapes
Weizmann Institute of Science, Israel
Lundi 16/07/2007, 14:15
Salle Claude Itzykson, Bât. 774, Orme des Merisiers
We pose the question: to what extent and under what conditions is the course of biological evolution predictable? The answer to this question is not obvious due to the interplay of deterministic selection and stochastic mutations. We address this issue for an initially maladapted asexual population evolving on fitness landscapes with many local optima. We find that whether the evolutionary trajectory is deterministic or stochastic depends on the effective mutational distance up to which the population can spread in the genotype space. We identify three broad regimes based on this distance: (i) deterministic quasispecies regime(ii) crossover from local quasispecies to stochastic evolution (iii) fully stochastic case.