Fig. 4. Homo- and heterotypic interaction strengths control multiphasicity. The change in the interaction energies of intermolecular homotypic interactions between proteins enriched in the (a) outer and (b) inner layers, (c) heterotypic interactions between the two proteins and (d) the difference between the outer–outer and inner–inner homotypic interactions for the system with the fittest individual. Purple curves correspond to the system where the outer protein was evolved and the inner was unchanged, and pink curves correspond to the converse. Error bars correspond to the standard deviation across three independent runs. Spherical droplets are shown for clarity; we use a slab geometry in direct-coexistence simulations.