Co-evolving cellular architectures by cellular programming

Recent studies have shown that non-uniform cellular automata (CA), where cellular rules need not necessarily be identical, can be co-evolved to perform computational tasks. This paper extends these studies by generalizing on a second aspect of CAs, namely their standard, homogeneous connectivity. It studies non-standard architectures, where each cell has a small, identical number of connections, yet not necessarily from its most immediate neighboring cells. It is shown that such architectures are computationally more efficient than standard architectures in solving global tasks, and also provide the reasoning for this. It is shown that one can successfully evolve non-standard architectures through a two-level evolutionary process, in which the cellular rules evolve concomitantly with the cellular connections.