Figure 3

Neighbourhoods in the model. a: The replication neighbourhood. X is an empty site; its four orthogonal nearest neighbour sites (von Neumann-neighbourhood) constitute the replication neighbourhood (grey), occupied by replicators S_1..4. b: The metabolic neighbourhood. X is an empty site; S₁ is a replicator on one of the four orthogonal nearest neighbour sites of the empty site. The metabolic neighbourhood of S₁ is the rectangular subgrid (in this case the Moore-neighbourhood) centred on S₁ (in grey). Metabolic neighbourhood size is one (h = 1). c: The catalytic neighbourhood. R_1..3 are replicases in the catalytic neighbourhood of S₁ (in grey). One of these replicators is drawn to help the replication of S₁ onto the empty site (X).