 The ambition to predict evolutionary trajectories, even for simple organisms, may turn out to be extremely difficult. But ESB provides new ways to investigate whether evolutionary pathways follow some recognizable dynamical patterns. Simulations of how gene regulatory networks change over evolutionary time-scales can be coupled to experimental evolution in bacteria or insects. For instance, the development of bacterial antibiotic resistance has been shown to be constrained by interactions between different mutations, which may make evolutionary biology informative also for the development and combination of antibiotics used in medical treatment (Palmer &amp; Krishony 2013; Weinreich et al. 2006).