Some Representational and Ecological Aspects of Evolvability

In this brief position paper I highlight a number of issues relevant to the evolvability of arti cial life systems. These issues became apparent over the course of my doctoral research which involved studying the evolutionary dynamics of a Tierra-like system (Taylor 1999a). The rst two issues (multifunctional phenotypic components and semantic closure) relate to the representation and function of individuals. The other two issues (embeddedness and ecological interactions) concern how individuals are related to the shared environment and to other individuals. While much of the recent work on evolvability has focussed on issues concerning individuals (e.g. genotype-phenotype mapping), which may give a system the capacity for high evolvability, I believe that the role of the ecological aspects of the system (e.g. the nal two issues addressed in this paper) in providing a drive for evolvability has been neglected; even if a system has the capacity for high evolvability, it will not realise this capacity if the appropriate selection pressures are absent.