M. Burtsev

K. Anokhin

P. Bateson

Based on computer simulations, we argue developmental plasticity accelerates evolution and drives organisms towards ever-greater complexity.

Developmental plasticity lets organisms meet new environmental challenges, but often at a cost. We show that such flexibility can accelerate evolution by allowing costly learned or induced responses to become encoded genetically. In model organisms, this effect grows as adaptive systems require more interacting parts, suggesting that plasticity becomes increasingly powerful as phenotypic complexity rises over time.

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 behaviour 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 an ever-greater complexity in biological organisation. Plasticity dramatically accelerates 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 is even greater when the number of elements needed to construct a functional system is increased. These results suggest that, as the difficulty of challenges from the environment becomes greater, plasticity exerts an ever more powerful role in meeting those challenges and in opening up new avenues for the subsequent evolution of complex adaptations.

Facilitation of evolution by plasticity scales with phenotypic complexity