Maximum likelihood estimates of the fraction of positively selected amino acid replacements (α). Values of α for genes with male-, female-, and unbiased expression were calculated using a maximum likelihood method . Genes with conserved bias between D. ananassae and D. melanogaster are indicated with solid boxes, genes with bias according to classification in D. ananassae (i.e. including conserved genes and genes with bias private to D. ananassae) are indicated with open boxes. Low frequency polymorphisms (≤ 15%) were excluded. Error bars indicate 95% CI. Asterisks indicate genes with a significant signal of positive selection (*P < 0.05, **P < 0.01).
Grath et al. BMC Evolutionary Biology 2009 9:291 doi:10.1186/1471-2148-9-291