Figure 4From: Functional organization and its implication in evolution of the human protein-protein interaction networkA dendogram reflecting the functional relationships for proteins from different temporal groups. The tree suggests a progressive functional change of the human PPI network during evolution. The observed clustering would not have occurred by random chance (P < 0.001). As indicated by the arrow, TG3 and TG4 in the tree are separately grouped into two clades, which are compared to the accelerated topology changes during this period as shown in Figure 3. TG: Temporal group.Back to article page