Where replication at the fiber end results in a mutation, the biased composition of the reservoir increases the likelihood that the next replicator macrocycle reverts to a building block composition that matches the original replicator composition, which amounts to error correction. Thus, growth from bound precursors improves the ability of a replicator fiber to maintain its composition during elongation. than that of the previously exposed hexamer and/or that of the other hexamers in the fiber. The fiber can 'correct' this error, making the composition of future hexamer(s) more likely to resemble that of the ones in the fiber, when the building block compositions of the fiber and the reservoir match.