Figure 2: Dating the paleopolyploidy event in P. equestris.

(a) Absolute age distribution obtained by phylogenomic dating of P. equestris homeologs. The solid black line represents the kernel density estimate of the dated homeologs, and the vertical dashed black line represents its peak, used as the WGD age estimate. Gray lines represent the density estimates for the 1,000 bootstrap replicates, and the vertical black dotted lines represent the corresponding 90% confidence intervals for the WGD age estimate. The original raw distribution of dated homeologs is also indicated by dots. The mode used as an estimate for the consensus WGD age is found at 75.57 million years ago with lower and upper 90% confidence interval boundaries at 71.50 and 80.73 million years ago, respectively y axis represents percentage of gene pairs. (b) Phylogenetic tree of the angiosperms. A wave of WGD events (indicated by colored bars) appears to be associated with the Cretaceous-Paleogene extinction event ∼66 million years ago²⁷. The orchid-specific WGD is indicated by the unfilled bar.