Assessment of evolutionary paths. a. Each data point represents an evolutionary path, plotted according to the number of evolutionary events separating the specialization of GAL1 and GAL3 and the switch effectiveness score. Scores improve as specialization events take place in closer succession (blue line indicates a linear regression, R2 = 0.85). b. Bars are mean path scores (+/- standard deviation indicated by error bars) for switch effectiveness in paths where loss of the GAL80 duplicate is the last evolutionary change and paths where GAL80 duplicate loss is not the last change. c. Each data point represents an evolutionary path, plotted according to their induction strength scores and the number of evolutionary events preceding Gal1p specialization. Scores worsen as more evolutionary events precede the specialization of GAL1 (green line represents the linear regression, R2 = 0.72). d. Data points are evolutionary paths, plotted according to the three scored network features. While there are paths that maximize both repression strength and switch effectiveness scores, it is not possible to simultaneously optimize either repression or effectiveness and induction strength in the same evolutionary path.