Fig. 1: Identification of WGD events in Poaceae and other Poales families.

A simplified Poaceae/Poales phylogeny (from the detailed tree in Supplementary Fig. 1) is shown with branch length representing the median estimated time (see Supplementary Fig. 2) from divergence to the present. Red lines in the tree represent Poaceae tribes, with the tribe names to the right of the terminal branches, and subfamily names further right. Other Poales families are shown as green branches and names. Other monocot orders are shown in pink. Horizontal blue bars at each node indicate the 95% credible interval of divergence time in millions of years. For major groups (indicated by dotted arrows), the numbers below the names and numbers within round brackets indicate the median value and the 95% confidence interval of divergence time millions of years ago, respectively. Stratigraphic periods of Triassic (Tr), Jurassic (J), Cretaceous (K), Paleogene (Pg), Neogene (Ng), and Quaternary (Q) are illustrated by colored boxes below the tree. WGD events are placed on branches with approximate divergence times and marked by numbered triangles, squares, or rhombuses in five different colors (See Supplementary Figs. 3–16 for detailed positions of WGDs; See Supplementary Figs. 17–23 and Supplementary Data 3 for detailed dating of WGDs). Green triangles, previously unknown WGDs. Pink rhombuses, WGDs that have different phylogenetic positions here with support from syntenic, phylogenomic, and Ks evidence. Orange rhombuses, WGDs that have different phylogenetic positions here with support from phylogenomic and Ks evidence. Red squares, WGDs with support from syntenic, phylogenomic and Ks evidence here and consistent with previous reports. Blue squares, WGDs with support from phylogenomic and Ks evidence here and consistent with previous reports. The red curve in the graph below the stratigraphic boxes illustrates the changes in oxygen isotope records of δ18O (‰) (the left Y-axis), reflecting the temperature changes as indicated by the right Y-axis. Left and right vertical yellow bars, respectively, indicates the J-K and Pg-Ng boundary with a 10 million years flanking period on either side. Source data are provided in a Source Data file.