We report in Table the parameters optimized through a series of test runs and finally used in this study. The algorithm terminates after a fixed number of generations, for which we verified that no significant improvement in fitness was observed anymore. The mating and mutation probabilities fix the fractions of the population that are respectively crossed or mutated. For a solution Θ, pc = 50% of its components are crossed with the SBX operator while the others remain unchanged. 75% of the population is mutated and the probability pm of mutating each gene is chosen so that one φ and one ψ backbone dihedral are modified on average. For gramicidin, the same probability applies to all 16 side chain dihedrals resulting in an average rate of 1.6 side chain mutants per individual. We choose a reasonable replacement of about 10% of the population by elites, unless otherwise specified, and also study the effect of no or stronger elitism in what follows.