Fig. 5

Mutational events in phase I (a), phase II (b) and both (c). The four historical environments are indicated with colours, with red, blue, green and purple corresponding to Ace, Gly, Glc, and Glu, respectively. Genes written in white have been affected by mutations in more than one historical environment. Genes written in colours have been affected by mutations in more than one replicate population from either identical historical environments during phase I or coming from identical historical environments during phase II, the colour corresponding to a given historical environment. Genes specific to the E. coli B ancestor strain are indicated with their ECB numbers. In a, mutated genes are dependent on the historical environment (Fisher exact test p = 0.039). In b, mutated genes are not influenced by the historical environment (Fisher exact test p = 0.981). In c, mutated genes are not influenced by the historical environment (Fisher exact test p = 0.562). Statistical tests were performed on genes written in white