Fig. 2.

Phenotypic response of hot-evolved flies. a Evolution of gene expression in the glycolysis pathway. Enzymes significantly up- (green) and down- (red) regulated in the hot-evolved populations relative to the ancestral population are shown in color. b Gene expression changes (log₂ fold change) in the hot-evolved populations relative to the ancestral (green) or cold-evolved (blue) populations. (** FDR < 0.05, * FDR < 0.1). c Hot-evolved populations (red) differ in gene expression from the ancestral (green) and cold-evolved (blue) populations for genes of the oxidative phosphorylation pathway and TCA cycle. d For both sexes, the resting metabolism of hot-evolved flies differs significantly from that of ancestral and cold-evolved populations. Both ancestral and cold-evolved populations are significantly different from the hot-evolved populations when considering both sexes in a single model (p = 0.032 and p = 0.003, respectively). Bars show mean ± 95% confidence intervals as estimated by our linear model (see Methods). e, f Higher fitness of hot-evolved flies: hot-evolved flies have a higher fecundity than the ancestral (p = 0.0006) or cold-evolved populations (p = 0.0018) at 23 °C but differ only from the ancestral populations at 28/18 °C (p < 0.0001), which is consistent with previous results in D. melanogaster (see Additional file 1: Supplementary Methods and Results for a detailed discussion)