An evolutionary scenario for members of the M. avium complex. (A) Depicted is a two-step inversion process as one possible scenario explaining how MAH evolved into MAP K-10 through MAP S397. To examine evolutionary relationship among the MAC, genome alignment around the inversion segment is depicted with Mauve version 2.3.1 . Divergence between MAH 104 and MAP sheep strains or between MAP sheep strains and cattle strains would take only one inversion, whereas divergence between MAH 104 and MAP cattle strains would need two independent inversion events. (B) Our proposed model for evolution of the M. avium complex.