Figure 4
From: Divergent evolution and purifying selection of the flaA gene sequences in Aeromonas
Pairwise comparisons of flaA sequences from 18 Aeromonas species and subspecies. Plot of maximum likelihood estimates of nonsynonymous (dN) against synonymous (dS) substitution rates (Fig. 4A), the straight line represents the neutral expectation (dN = dS). The ω ratio (dN/dS) plotted against the maximum likelihood estimates of sequence divergence (t), defined as the expected number of nucleotide substitutions per codon (Fig. 4B).