Selection, Space and Diversity: What Can Biological Speciation Tell Us About the Evolution of Modularity?

Modularity is a widespread form of organization in complex systems, but its origins are poorly understood. Here, I discuss the causes and consequences of modularity in evolutionary systems. Almost all living organisms engage in sexual exchange of genes, and those that do so are organized into discrete modules we call species. Gene exchange occurs within, but not between, species. This genetic segregation allows organisms to adapt to different niches and environments, and thereby evolve complex and long-lasting ecosystems. The process that generates such modularity, speciation, is therefore the key to understanding the diversity of life. Speciation theory is a highly developed topic within population genetics and evolutionary theory. I discuss some lessons from recent progress in speciation theory for our understanding of diversification and modularity in complex systems more generally, including possible applications in genetic algorithms, artificial life and social engineering.