SKM 2023 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 27: Statistical Physics: Far From Equilibrium I

DY 27.1: Invited Talk

Wednesday, March 29, 2023, 09:30–10:00, ZEU 250

Evolution in changing environments and driven disordered systems — •Joachim Krug, Suman Das, and Muhittin Mungan — Institute for Biological Physics, University of Cologne, Köln, Germany

Biological evolution is governed by the fitness landscape, a map from the genetic sequence of an organism to its fitness. A fitness landscape depends on the organism’s environment, and evolution in changing environments is still poorly understood. After introducing the concept of fitness landscapes and their mathematical description, the talk will focus on a particular model of antibiotic resistance evolution in bacteria [1]. Tradeoffs between adaptation to low and high concentration lead to a rugged landscape with an exponentially large number of fitness peaks. With evolutionary dynamics that follow fitness gradients, resistance evolution under slowly changing antibiotic concentration maps to the zero temperature dynamics of a disordered spin system [2]. Specifically, the set of genetic sequences that form a fitness peak at some concentration maps exactly to the metastable states in an equivalent Preisach system, a paradigmatic model of hysteresis in random magnets. Making use of the conceptual tool of state transition graphs developed in the context of driven disordered systems, we quantify the degree of genotypic and phenotypic reversibility in the response of the population to antibiotic concentration cycling.

[1] S.G. Das, S.O.L. Direito, B. Waclaw, R.J. Allen, J. Krug, eLife 9:e55155 (2020)

[2] S.G. Das, J. Krug, M. Mungan, Phys. Rev. X 12:031040 (2022)