Downregulated genes are female-biased. a) There is a significant negative correlation between wild-type sex-bias in expression and changes in expression after experimental evolution in males. This relationship holds regardless of genomic location. Positive wild-type gene expression values indicate female-biased expression and negative values indicate male-biased expression. Both sex-biased expression (female to male) and experimental evolution fold change are plotted on a log₂ scale. b) There is a negative correlation between significant differentially expressed genes located on the X chromosome (shown in coral) and sex-biased expression in females. Only 22 genes were located on autosomes (shown in blue).