Final answer:
The relation between phenotypic trait variation and environmental variable variation is called a reaction norm, which is a measure of phenotypic plasticity.
Step-by-step explanation:
The relation between the variation in a phenotypic trait and the variation in an environmental variable, or the pattern of phenotypic plasticity in a trait, is called a reaction norm. Phenotypic plasticity refers to the ability of an organism to change its phenotype in response to changes in the environment. As environmental conditions fluctuate, a fit phenotype is crucial, and this phenotypic variance is a form of adaptation that helps in the survival and reproduction of organisms. This adaptation arises when a change in the range of genetic variation enhances or maintains the population's fitness in its environment. For instance, the variation in finch beaks enables adaptation to different food availabilities, exemplifying this concept.
The relation between the variation in a phenotypic trait and the variation in an environmental variable is called phenotypic plasticity. It refers to the ability of an organism to change its phenotype in response to environmental cues.
The relation between the variation in a phenotypic trait and the variation in an environmental variable is called phenotypic plasticity. Phenotypic plasticity refers to the ability of an organism to change its phenotype or trait in response to environmental cues. It allows organisms to adapt to different environmental conditions without any changes in their genetic makeup.