Fig. 3

Divergence dating and the reconstruction of historical biogeography. Numbers on the nodes represent medians of estimated divergence date, and the horizonal bars show 95% highest posterior density of these estimates. Stars indicate the positions of fossil constrains used for the calibration of molecular clock (see Table 3 for more details). Different colours on the nodes represent reconstructed ancestral regions for each clade, according to the map in the frame: South Africa region (S), Zambezian region (Z), Somali region (E), Sudanian region (W), Sahara region (N), Arabian region (A)