Fig. 4.

Consistent changes in allele frequencies associated with elevated CO₂ in multiple SNPs within single genes. Genes are in functionally enriched categories related to lipid metabolism (highlighted in red), ion homeostasis (blue), or both (purple); these six genes represent many in these categories that have multiple SNPs per gene showing greater than average change in allele frequency and are enriched for response to high CO₂ after 1 and 7 d. For 13 of 18 SNPs shown, changes in allele frequency are in the same direction after 1 d in elevated CO₂ conditions (day 1–900 µatm) as after 7 d in elevated CO₂ conditions (day 7–900 µatm) relative to allele frequencies in the wild (day 1–400 µatm). See Fig. 5 for data from SNPs in genes enriched for change after both 1 and 7 d in high CO₂ culture. Numbers indicate base position of the polymorphism in the coding region of the gene. Bars are mean frequencies (±SE) in seven populations. Asterisks mark amino acid changing polymorphisms.