Design Strategies for Open-Ended Evolution

Abstract

Open-endedness is an important goal for designing systems that can autonomously find solutions to combinatorically-complex and ill-defined problems. We distinguish two modes of creating novelty: combinatoric (new combinations of existing primitives) and creative (new primitives). Although combinatoric systems may differ in numbers of possible combinations, their set of possibilities is closed. Creative systems, on the other hand, have open-sets of possibilities because of the partial- or ill-defined nature of the space of possible primitives. We discuss classes of adaptive and self-modifying cybernetic robotic devices in terms of these two kinds of processes. We consider material systems constructed from genetically-directed pattern-grammars. Although spaces of accessible structures are closed, function spaces can nevertheless be open. Thus, genome sequence spaces and gene-product structure spaces are regarded as closed, while partially-defined, phenomic function-spaces are potentially open.