Development as a Factor in the Evolution of Modularity in Biological Systems

Biological networks and other systems tend to be modular in structure, with reuse of motifs and the ability to be separated into semi-independent units. The evolutionary forces that produce this modularity are a topic of active research, as modular solutions rarely emerge from models of biological evolution. Through simulations combining evolution and development, I investigate the role that development plays in the emergence of modularity, using a popular metric for network modularity and representing non-network structures as networks in which building blocks are nodes and connections between them are arcs. Preliminary results show that the modularities of structures evolved by an L-systems-based evolutionary developmental algorithm are higher than those evolved by a non-developmental evolutionary algorithm that models evolution in the same way. To ensure that these results are not specific to a single algorithm, I am conducting evolutionary developmental simulations using other methods for simulating development, evolving both networks and building-block structures. This study sheds light on the role of development as a factor in the origin of modularity in biological networks and other biological systems.