The ability of an organism to adapt to changes in its environment by modifying its own development, form, behaviour, or other trait. Hence it depends on the capacity for a given genotype to respond to environmental factors and to adjust the phenotype accordingly. Plasticity is of great selective advantage in an unstable or unpredictable environment and can itself be inherited and evolve. Plants typically have marked phenotypic plasticity, showing considerable variation in, among other characters, mature height, seed number, and seed mass with different growing conditions, including factors such as light intensity, daylength, and temperature. Seasonal factors and the availability of food also affect the course of development in many animals. Social insects (such as bees) with the same genotype undergo different developmental pathways to become members of different castes, depending on diet and incubation temperature. Modification of an animal’s behaviour through learning is another instance of the great importance of phenotypic plasticity.