Tracking the Evolution of Chemical Computing Networks

How do chemical reaction networks that process information evolve? This is not only a fundamental question in the study of the origin of life, but also in diverse fields like molecular computing, synthetic biology, and systems biology. Here, we study the evolution of chemical flip-flops by means of chemical organisation theory. Additionally, we compare evolved circuits with manually constructed ones. We found that evolution selects for an organisational structure that is related to function. That is, the resulting computation can be explained as a transition between organisations. Furthermore, an evolutionary process can be tracked as a change of the organisational structure, which provides a fundamentally different view than looking at the structural changes of the reaction networks. In our experiments, 90% of evolutionary improvement coincide with a change in the organisational structure. We conclude that our approach provides a novel and useful perspective to study evolution of chemical information processing systems.