Fig. 5.

Selection in action. There is a greater magnitude of change in allele frequency after 7 d than 1 d in elevated CO₂ conditions (red and black, respectively) in the same suite of genes. Change in allele frequency for the same set of 4,782 SNPs comparing day 1–400 µatm with day 1–900 µatm (black) and day 1–900 µatm with day 7–900 µatm (red) are represented in each distribution. These SNPs are in the 601 genes in common (71% overlap) in functional categories enriched for change in allele frequency in response to high CO₂ conditions after 1 and 7 d (Tables S4 and S5). Distributions are significantly different (K-S test; P < 0.0001).