Plasticity facilitates rapid evolution

Abstract

Developmental plasticity enables organisms to cope with new environmental challenges. If deploying such plasticity is costly in terms of time or energy, the same adaptive behavior could subsequently evolve through piecemeal genomic reorganisation that replaces the requirement to acquire that adaptation by individual plasticity. Here we report a new dimension to the way in which plasticity can drive evolutionary change leading to ever greater complexity in biological organization. Our model deploys the concept of partially overlapping functional systems. We found that plasticity accelerated dramatically the evolutionary accumulation of adaptive systems in model organisms with relatively low rates of mutation. The effect of plasticity on the evolutionary growth of complexity was even greater when the number of elements needed to construct a functional system was increased. These results suggest that as the difficulty of challenges from the environment become greater, so plasticity exerts an ever more powerful role in meeting those challenges and in opening up new avenues for the subsequent evolution of complex adaptations.