Quantitative Analysis of Evolvability using Vertex Centralities in Phenotype Network

In an evolutionary system, robustness describes the resilience to mutational and environmental changes, whereas evolvability captures the capability of generating novel and adaptive phenotypes. The research literature has not seen an effective quantification of phenotypic evolvability able to predict the evolutionary potential of the search for novel phenotypes. In this study, we propose to characterize the mutational potential among different phenotypes using the phenotype network, where vertices are phenotypes and edges represent mutational connections between them. In the framework of such a network, we quantitatively analyze the evolvability of phenotypes by exploring a number of vertex centrality measures commonly used in complex networks. In our simulation studies we use a Linear Genetic Programming system and a population of random walkers. Our results suggest that the weighted eigenvector centrality serves as the best estimator of phenotypic evolvability.