Genetic diversity in metabolic pathways. 657 genes with EC numbers were mapped to the corresponding metabolic pathways in the KEGG database  and sorted based on the nucleotide diversity (π) estimator of the selection acting on the gene. Different letters (on the right) mean statistically significant differences (Kruskal-Wallis test, P < 0.0013; a posteriori test P < 0.05).
Ackermann et al. BMC Genomics 2012 13:736 doi:10.1186/1471-2164-13-736