Evolutionary Progress in Heterogeneous Cellular Automata (HetCA)

Although very controversial in the field of evolutionary biology, the notion of evolutionary progress is nevertheless generally accepted in the field of Artificial Life. In this article we adopt the definition proposed by Shanahan (2012) to study the existence of evolutionary progress in an evolutionary simulation which we call HetCA. HetCA is a heterogeneous cellular automata characterized by its ability to generate open ended long-term evolution. In this study, we measure evolutionary progress on three criteria: the robustness, size and density of generated genotypes. Our results demonstrate that the oldest genotypes are frequently the most robust, and that phenotypic density is higher for genotypes collected later in the evolutionary process.