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DY: Fachverband Dynamik und Statistische Physik

DY 32: Statistical Physics in Biological Systems III (organised by BP)

DY 32.6: Talk

Thursday, March 17, 2011, 12:00–12:15, ZEU 260

Stochastic tunneling in a two-locus system with recombination — •Andrej Fischer, Ivan Szendro, Joachim Krug, and Alexander Altland — Institut für Theoretische Physik, Universität zu Köln, D-50973 Köln, Germany

The analysis of minimal models in population genetics is an important conceptual task. The effects of mutation, selection and drift (finite population size) on evolution are captured by Kimura’s well-known one-locus model with two alleles. Here, we analyze a model that includes additionally the effects of epistasis and recombination in a two-locus setting. For sign epistasis, i.e. the over-compensation of an initial deleterious point mutation by a beneficial secondary mutation at the other locus, the fixation of the fittest genotype is dominated by the presence of several bottlenecks. The interplay of both finite size effects and meta-stability induced by recombination make for intricate fixation dynamics in this paradigmatic model system. Both analytical and numerical results are presented.