Understanding Inherent Qualities of Evolved Circuits: Evolutionary History as a Predictor of Fault Tolerance

Electronic circuits exhibit inherent qualities, which are due to the nature of the design process rather than any explicit behavioural specifications. Circuits designed by artificial evolution can exhibit very different inherent qualities to those designed by humans using conventional techniques. It is argued that some inherent qualities arising from the evolutionary approach can be beneficial if they are understood. As a case study, the paper seeks to determine the underlying mechanisms that produce one possible inherent quality, 'Populational Fault Tolerance', by using various strategies including the observation of constituent components used throughout evolutionary history. The strategies are applied to over 80 evolved circuits and provide strong evidence to support an hypothesis - that Population Fault Tolerance arises from the incremental nature of the evolutionary design process. The hypothesis is used to predict whether a given fault should manifest the quality, and is accurate in over 80% of cases.