Developmental Encodings Promote the Emergence of Hierarchical Modularity

While it has been observed (Hornby et al., 2001) that developmental encodings in evolved systems may promote modularity, there has been little quantitative study of this phenomenon. There has also been little study of the factors driving the emergence of hierarchical modularity modularity on multiple levels, in which the modules found at a finer-grained level can serve as elements in a coarser-grained network that is also modular despite the fact that most fields with an interest in modularity, including biology and engineering, define hierarchy as an important aspect of modularity. We examine the effect of developmental encodings on the emergence of multiple levels of modularity through the lens of two developmental systems, GRNEAT and GENRE, and find evidence that developmental encodings promote this emergence of modular hierarchy.