Evolutionary history of the human Rabs. Losses and gains of Rabs from the last eukaryotic common ancestor (LECA) towards Homo sapiens. The six supergroups are indicated by their name on the right and the common color scheme. The time points of major remodeling of the human Rab proteins are shown on the top. Most gains in the Rab repertoire are associated with the transition to multicellularity or the rise of vertebrates. In addition, there are two Rab proteins that are specific to primates (Rab40a, Rab40aL), Rab41 is present only in primates and dolphins, and Rab6c seems to be specific to Hominidae. The losses of RabX1, Rab29, RabX4, and RabX6 are indicated by their lines terminating somewhere between the development of multicellularity and the rise of the vertebrates.
Klöpper et al. BMC Biology 2012 10:71 doi:10.1186/1741-7007-10-71