Fig. 3

Species tree and 4DTv of set 1. a Species tree of the group of Lamiales including the additional two Oleaceae species. Bars on the right show the taxonomic classification. Duplication nodes for which 4DTv values of the paralogous pairs were calculated are marked with letters (A to E) as referred to in the text and colored according to each evolutionary age. The species used to calculate the 4DTv of orthologs pairs are shown in different colors. b Distributions of 4DTv values for the orthologous pairs between O. europaea and P. angustifolia, F. excelsior, J. sambac, and S. indicum, respectively. Colors correspond to the species in (a). The peaks of the orthologous pairs mark speciation events. Hence, considering that earlier events are on the left (lower 4DTv values), the order of speciations is in agreement with the species tree. c 4DTv of the paralogous pairs of O. europaea at the marked nodes in the tree. Each peak marks duplication events. Colors and letters correspond to nodes marked in (a)