When evolution realizes large deviations of fitness: from speciation to dynamical phase transitions

TL;DR

This paper connects evolutionary dynamics with large-deviation theory, showing how population genome transitions can be understood as dynamical phase transitions through a novel mapping, applicable to Moran models and beyond.

Contribution

It introduces a new mapping between evolution and large-deviation theory, enabling the study of population genome transitions as dynamical phase transitions.

Findings

Large population limit leads to large-deviation dynamics for genome exploration.

Transitions in genome distribution are interpreted as dynamical phase transitions.

Mapping extends beyond Moran models to more general evolutionary frameworks.

Abstract

We explore the connection between evolution and large-deviation theory. To do so, we study evolutionary dynamics in which individuals experience mutations, reproduction, and selection using variants of the Moran model. We show that, in the large population size limit, the impact of reproduction and selection amounts to realizing a large-deviation dynamics for the non-interacting random walk in which individuals simply explore the genome landscape due to mutations. This mapping, which holds at all times, allows us to recast transitions in the population genome distribution as dynamical phase transitions, which can then be studied using the toolbox of large-deviation theory. Finally, we show that the mapping extends beyond the class of Moran models.