The evolutionary role of mutational robustness: theoretical insights

Mutational robustness, the ensemble of mechanisms that allow organisms to maintain a stable phenotype despite genetic mutations, affects adaptive evolution in several ways. Many models have attempted to explain how mutational robustness might evolve and shape adaptation, but the variety of approaches and assumptions complicates a clear synthesis. Here, we categorize and critically discuss the main approaches for modeling the evolutionary causes and consequences of mutational robustness. We discuss how robustness can emerge from aspects of biological organization (e.g., modularity, critical dynamics) and selection (e.g., stabilizing selection) and how robustness can both enhance and constrain evolvability [e.g., through cryptic genetic variation (CGV)]. We conclude by discussing challenges related to model complexity and computational cost and outline the foremost outstanding questions.