Fig. 1.
Proteins under strong purifying selection increase their rates of evolution after the WGD. a Frequency distribution of the Likelihood-Ratio Test (LRT) values for the hypothesis test comparing two evolutionary models. Orange bars indicate orthogroups in which the null hypothesis of a single dN/dS across the phylogeny is rejected in R1 (rate-change, ω0 ≠ ωwgd); blue bars are orthogroups for which the null hypothesis cannot be rejected (constant-rate, ω0 = ωwgd). b Cumulative distribution plots comparing the average dN/dS ratios of non- and post-WGD branches. c Scatter plot comparing post-duplication to pre-duplication dN/dS ratios in 535 orthogroups. Purple bars of the x-axis histogram indicate orthogroups under strong purifying selection in non-WGD branches (dN/dS < 0.02) whereas lime bars are those under weak to moderate purifying selection. Each dot is a single orthogroup; orange dots are those in which the null hypothesis is rejected (rate-change, ω0 ≠ ωwgd), while cyan dots are orthogroups in which the null hypothesis cannot be rejected. d Fraction of orthogroups under strong (purple bar) or weak to moderate (lime bar) purifying selection in which the alternative hypothesis (rate-change, ω0 ≠ ωwgd) is accepted