Evolution of a population of random Boolean networks

TL;DR

This study explores how populations of random Boolean networks evolve under selection for robustness, revealing slow connectivity changes and diverse network adaptations despite maximum fitness plateau.

Contribution

It demonstrates the evolutionary dynamics of Boolean networks under robustness selection, highlighting the effects of mutation rates and the structure of the fitness landscape.

Findings

Higher mutation rates lead to increased robustness.

Populations remain near maximum fitness plateau but diverge in network space.

Evolution causes slow changes in network connectivity and fitness.

Abstract

We investigate the evolution of populations of random Boolean networks under selection for robustness of the dynamics with respect to the perturbation of the state of a node. The fitness landscape contains a huge plateau of maximum fitness that spans the entire network space. When selection is so strong that it dominates over drift, the evolutionary process is accompanied by a slow increase in the mean connectivity and a slow decrease in the mean fitness. Populations evolved with higher mutation rates show a higher robustness under mutations. This means that even though all the evolved populations exist close to the plateau of maximum fitness, they end up in different regions of network space.