In case (ii) (E AA =-2, E BB =0, and E AB =-1, seeded with A6B0 fibers), the replicators that grew on the A6B0 fiber seeds were considerably enriched in A-rich hexamers (Figure ). Replication of A6B0 from surface-bound precursors exhibited an error rate of 0.73, while in the control without surface binding this rate was 0.86 (Figure ). Thus, the fidelity of replication of A6B0 benefits from precursor binding. However, this effect appears limited to this particular replicator. Since there is an appreciable cross-interaction between A and B in this case (E AB =-1) error rates for the other ring compositions are relatively high. In addition, as the precursors bound to the surface are enriched in A (as a result of the seed being composed solely of A building blocks) replication of rings containing increasing fractions of B becomes increasingly difficult and therefore error prone.