Next, we compared the evolutionary rates of the GII.P16-GII.2 and GII.P2-GII.2 strains. To gain statistical significance, we collected the nucleotide sequences of the GII.P2-GII.2 strains (25 strains) from GenBank, but we could not collect a sufficient number of the GII.P12-GII.2 and GII.Pe-GII.2 sequences from the GenBank to reach statistical significance. The evolutionary rate of GII.P16-GII.2 (1.838 × 10−3 substitutions/site/year; mean ± 95% HPD: 1.237–2.456 × 10−3 substitutions/site/year) was greater than that of GII.P2-GII.2 (1.712 × 10−3 substitutions/site/year; mean ± 95% HPD: 0.957–2.41 × 10−3 substitutions/site/year) (p = 7.891 × 10−135).