Fig. 3

Relative divergence times and evolutionary rates of S. mansoni glucose transporters. The figure displays the relative divergence times of selected nodes from the ML tree topology in Fig. 1. Class I glucose transporters (node 2) and Platyhelminthes-specific cluster of glucose transporters (node 10) (Panel a). Divergence times for selected branching points were calculated in the 100 most parsimonious trees using the ML method based on the LG model (see Methods). Node 2 (average of relative time of divergence: 0.68, Std: 0.02) is older than node 10 (average of relative time of divergence: 0.28, Std: 0.009) with p-value < 0.0001. The colored scale shows the relative evolutionary rates among selected branches (Panels a and b). The evolutionary rate (evol rate) measured as the relative number of amino acid substitutions per site was calculated for selected nodes in the 100 most parsimonious trees using RelTime method [22]. The glucose transporters SGTP2 (average of evol rate: 3.6, Std: 0.42) and SGTP3 (average of evol rate: 4.9, Std: 0.81) evolved faster than SGTP1 (average of evol rate: 0.13, Std: 0.028) and SGTP4 (average of evol rate: 1.6, Std: 0.067) with a p-value < 0.0001 (Panel c)