Fig. 3
From: Weak gene–gene interaction facilitates the evolution of gene expression plasticity
Persistence versus evolution of expression plasticity over the course of adaptation. A A schematic for distinction between plasticity persistence and plasticity evolution. Briefly, with two measures—GC and GCb—obtained from the studied Rufous-capped Babbler populations, plasticity persistence, and plasticity evolution refer to situations where, respectively, the two measures are about equal to and substantially different from each other. B After empirically examining the distributions of the GCb-to-GC ratios in our cases (brain- or liver-expressed ACDE genes, two measures derived based on either population L1 or L2), we defined plasticity persistence and plasticity evolution to be with ranges of the ratio as 1 ± 0.5 and 0 ± 0.5, respectively. C Percentages of ACDE genes that each exhibits either reinforcing or reversing expression plasticity (RI and RV, respectively) undergo plasticity persistence and plasticity evolution. Varied proportions of plasticity evolution between categories (RI vs. RV) are evaluated by two-sided Fisher exact tests (*** and blanks indicate P < 0.001 and > 0.05, respectively)