Frequency histogram of Hamming distance values between MS2 and all other mutants. Color codes are the same as previous figures. The x-axis corresponds to the Hamming distances calculated between each mutant type and the sequence of the MS2, and the y-axis correspond to the frequency at which mutants with that specific Hamming distance are present in the populations (sum of lineages 6H and 6L). Note that overall, the most frequent mutants have a Hamming distance of one compared to MS2, and most of them constitute the MS1 (127 out of 170). The groups with large Hamming distance values are B16-19, used to start the experiment (and once replaced did not come back), and MS3 (the least recurrent of all the MS). The majority of the mutant sequences that have appeared at one burst have recurred at another burst (61%), mainly as a master sequence.