Individuals.

As suggested by the analysis of self-reproduction in Section 7.2.3, individual replicators should have the capacity for indefinite heredity if they are to participate in a process of open-ended evolution. Additionally, it is desirable that the copying process (von Neumann's automaton B) is implicit in the environment, at least at the start of the evolutionary process. Moreover, these individuals should have other selectable properties as well. Initially, these properties might be directly associated with the individual's structure (e.g. catalytic capabilities), although the potential should also exist for the evolution of a more indirect translation from genotype to phenotype.

Formulated in this way, the focus shifts from self-reproduction to questions concerning what other kinds of processes could or should be associated with the individuals. In other words, what is their `phenotype space'? It has often been noted that open-ended evolution requires that the domain of interaction of the replicators is within the evolving system itself. Furthermore, in Section 7.2.3 it was also argued that individuals should be fully embedded within the arena of competition.