Figure 2From: The impact of horizontal gene transfer in shaping operons and protein interaction networks – direct evidence of preferential attachmentDistribution of evolutionary rates (dN/dS) for various E. coli strains overlaid on a phylogenetic tree using E. coli K12 as reference for genome comparisons. Core genes evolve slower than Non-core and HGT genes (P-value < 0.001).Back to article page