Figure 4.

The GAL clusters of three lineages were acquired by HGT. (A) Diagrammatic representation of AU tests performed. The null tree was constrained to follow the species tree, except for the three HGT candidate lineages, which were placed by ML (dashed, lightly colored; Supplementary Figures S7–S10). Three alternative hypotheses were tested that independently constrained a single HGT candidate to its placement in the species tree (solid, darkly colored). Constraint trees used in the AU tests are provided in Supplementary Figure S11. (B) P-values of the AU tests are shown. All tests significantly reject their alternative constrained topologies and vertical inheritance, which is consistent with HGT as the mechanism of reacquisition.