Adaptation and irreversibility in microevolution

Abstract

Within the framework of population genetics we consider the evolution of an asexual haploid population under the effect of a rapidly varying natural selection (microevolution). We focus on the case in which the environment exerting selection changes stochastically. We derive the effective genotype and fitness dynamics on the slower time-scales at which the relevant genetic modifications take place. We find that, despite the fast environmental switches, the population manages to adapt on the fast time-scales yielding a finite positive contribution to the fitness. However, such contribution is balanced by the continuous loss in fitness due to the varying selection so that the statistics of the global fitness can be described neglecting the details of the fast environmental process. The occurrence of adaptation on fast time-scales would be undetectable if one were to consider only the effective genotype and fitness dynamics on the slow time-scales. We therefore propose an experimental observable to detect it.

19 pages, 2 figures. Revised version

References in corpus (9)

• Stochastic thermodynamics, fluctuation theorems, and molecular machines
• Mobility promotes and jeopardizes biodiversity in rock-paper-scissors games
• Stochastic Models of Evolution in Genetics, Ecology and Linguistics
• Fluctuation Relations for Diffusion Processes
• Anomalous thermodynamics at the micro-scale
• A Model for the Generation and Transmission of Variations in Evolution
• Adaptive evolution of molecular phenotypes
• Fitness in time-dependent environments includes a geometric contribution
• Speeding up evolutionary search by small fitness fluctuations

Cited by in corpus (2)

• Multiple-scale stochastic processes: decimation, averaging and beyond
• Entropy production of a Brownian ellipsoid in the overdamped limit