Javier Macía, Ricard Solé

Paper #: 08-02-005

Evolved natural systems are known to display some sort of distributed robustness against the loss of individual components. Such type of robustness is not just the result of redundancy. Instead, it seems to be based on degeneracy, i. e., the ability of elements that are structurally different to perform the same function or yield the same output. Here we explore the problem of how relevant is degeneracy in evolved digital systems, and what types of network structures underlie the resilience of evolved designs to the removal or loss of a given unit. It is shown that fault tolerant circuits are obtained only if robustness arises in a distributed manner. No such reliable systems are reached just by means of just redundant organization, thus suggesting that reliable designs are necessarily tied to degeneracy.