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DY: Fachverband Dynamik und Statistische Physik

DY 22: Posters - Statistical Physics of Biological Systems

DY 22.3: Poster

Dienstag, 21. März 2017, 14:00–16:00, P1A

Interference of deleterious and beneficial mutations in spatial habitats — •Philipp Klatt and Joachim Krug — Institute for Theoretical Physics, Cologne, Germany

One of the fundamental questions of population genetics is that of the rate at which beneficial or deleterious mutations are generated and incorporated into asexual populations. The quantity which describes this process is the speed of evolution. We here study a spatially structured model in which individuals of a population only compete locally on the time scale of a generation. In contrast to well-mixed models, where individuals compete with the whole population, the speed of evolution tends to a finite value in the limit of infinite habitat size when all mutations are either beneficial or deleterious [1,2]. We consider the general case where both types of mutations are present and map out the dependence of the speed of evolution on several parameters by interpreting analytical and numerical results. In contrast to the well-mixed case, we find that large populations undergoing a fitness decline caused by the accumulation of deleterious mutations (Muller’s ratchet) cannot be rescued by a small rate of beneficial mutations. Moreover, the effects of deleterious and beneficial mutations on the speed of evolution are generally not additive, suggesting a nontrivial interference between the two types of mutational effects.

[1] Martens, E.A. and Hallatschek, O. (2011). Interfering waves of adaptation promote spatial mixing. Genetics 189:1045-60.

[2] Otwinowski, J. and Krug, J. (2014). Clonal interference and Muller’s ratchet in spatial habitats. Physical Biology 11:056003.