Regensburg 2010 – scientific programme
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DY: Fachverband Dynamik und Statistische Physik
DY 2: Statistical Physics of Biological Systems I (joint session of BP + DY)
DY 2.3: Talk
Monday, March 22, 2010, 11:00–11:15, H45
The number of adaptive paths in fitness landscapes with sign epistasis — •Jasper Franke1, Alexander Kloezer1, Joachim Krug1, and J. Arjan G.M. de Visser2 — 1Institut für Theoretische Physik, Universität zu Köln — 2Laboratory of Genetics, Wageningen University
A mutation of an organism’s (genotypic or phenotypic) configuration has a higher probability of becoming fixed in the population if it increases the mutant’s degree of adaptation to the environment (the organism’s ‘fitness’). A sequence of fitness-improving mutations forms an adaptive path along which the population can evolve. This concept of accessible paths plays an important role in determining the possible configurations that can be reached by evolutionary adaptation.
Since the mapping from configuration to fitness is biochemically only partially understood, several statistical models have been proposed trying to capture the essential features.
In this contribution, we consider the expected number of accessible paths and the probability of not having any accessible paths at all. We present analytic and numerical results for three statistical models for fitness landscapes and compare these results to data for the fitness landscape of the fungus Aspergillus niger.