Figure 4. Pseudogenes and evolution of host adaptation across the AESB.

(a) Relative frequency of pseudogenes for each strain of the AESB. Ancient genomes are identified and host generalists are shown in blue and host adapted in orange. (b) Illustration of model used to infer evolution towards host adaptation. (c) Simulated expectation of candidate genes (phoN in green, ydcK in beige) to harbour randomly distributed pseudogenization events using 10,000 simulations. (d) Host adapted S. enterica serovars that harbour a phoN or ydcK pseudogene. BA: Bronze Age, Tepos: 16^th century Mexican.