English: The plotted line reflects fluctuations in variability amongst aligned 16S rRNA gene sequences of 79 Pseudomonas type strains. Variability for each base position was generated as follows: one minus the frequency of the most common nucleotide residue. The resulting frequency distribution was then smoothed by taking the mean frequency within a 50-base sliding window, moving 1 base position at a time along the alignment. Peaks correspond to the known V1 to V9 hypervariable regions.