Shifting gears: Thermodynamics of genetic information storage suggest stress-dependence of mutation rate, which can accelerate adaptation

TL;DR

This paper proposes a thermodynamic model showing that genetic mutation rates depend on stress levels, which can accelerate adaptation without genetic changes, impacting evolutionary theory and disease evolution.

Contribution

It introduces a physical constraint-based explanation for stress-dependent mutation rates, challenging the traditional view of fixed mutation rates in evolution.

Findings

Mutation probability depends on metabolic resources and stress levels.

Stress-dependent mutation rates can accelerate adaptation.

Mutation rate variability occurs within the same genotype depending on stress.

Abstract

Background: Acceleration of adaptation dynamics by stress-induced hypermutation has been found experimentally. Evolved evolvability is a prominent explanation. We investigate a more generally applicable explanation by a physical constraint. Methods and Results: A generic thermodynamical analysis of genetic information storage obviates physical constraints on the integrity of genetic information. The capability to employ metabolic resources is found as a major determinant of mutation probability in stored genetic information. Incorporation into a non-recombinant, asexual adaptation toy model predicts cases of markedly accelerated adaptation, driven by a transient increase of mutation rate. No change in the mutation rate as a genetic trait is required. The mutation rate of one and the same genotype varies dependent on stress level. Implications: Stress-dependent mutation rates are physically necessary and challenge a condition-independent genotype to mutation rate mapping. This holds implications for evolutionary theory and pathogen and cancer evolution.