Figure 1

Evolutionary tree depicting the relationship of the different Rab families that were potentially present in the last eukaryotic common ancestor (LECA). The tree was constructed as described in the Methods section; we removed any groups that were difficult to place (Rab19, Rab33, Rab34, Rab44 and Rab45) from the tree. Statistical support is shown for edges that support major Rabs groups, or a LECA Rab group, or show unexpected splits, and also for the colored surroundings associated with the edge, with the first number of the pair being the likelihood-mapping value and the second being the almost unbiased test (AU) value [91]. All supergroups are clearly separated, and most LECA groups showed good statistical support. Exceptions generally showed better support in their corresponding supergroup trees (see Additional file 2). For example, the analysis indicated that Rab22 is a close relative of Rab5. Separating Rab5 and Rab22 was complicated by protozoan duplications of Rab5, which have drifted away from their ancestor and are often placed very close to Rab22.