Chapter 3 - Evolutionary Gene Regulatory Networks and Biochemical Networks

Abstract

In the evolutionary process, the random transmission and mutation of genes provide biological diversities for natural selection. In order to preserve functional phenotypes between generations, gene networks need to evolve robustly under the influence of random genetic perturbations and environmental disturbances. Therefore the robustness of the phenotype exerts a selection force on gene networks to keep network functions. However, gene networks need to adjust by variations in genetic content to generate phenotypes for new challenges in the network's evolution, meaning the evolvability. Hence, there should be some interplay between the evolvability and network robustness in evolutionary gene networks. In this chapter, we discuss the interplay between the evolvability and network robustness of a gene network and a biochemical network from a nonlinear stochastic system point of view, and the tradeoff between the genetic robustness and environmental robustness in evolution from the viewpoint of the stochastic stability robustness and sensitivity of the nonlinear stochastic biological network.