Table 1 Error-prone PCR nucleotide mutation spectrum. Spectrum of nucleotide mutations introduced by the error-prone PCR procedure used in the neutral evolution experiments. The spectrum was determined by sequencing the four final (generation 12) sequences from the unselected population, as in these sequences the mutations accumulate without constraint. As has been previously noted for error-prone PCR with Taq polymerase [3,5,27], the nucleotide error spectrum is biased towards certain types of mutations.

From: Evolution favors protein mutational robustness in sufficiently large populations