Final answer:
A site that has variation within the members of the population is said to be polymorphic. This means that there are multiple variations of particular characteristics within the population. Geographic separation can also lead to differences in phenotypic variation.
Step-by-step explanation:
A site that has variation within the members of the population is said to be polymorphic. Polymorphism refers to the presence of multiple variations of particular characteristics within a population.
For example, in a population of domestic dogs, there can be a variety of fur colors and patterns, which represent the different variations or phenotypes within the population. This variation can arise due to factors such as genetic structure and the environment.
Geographic separation between populations can also lead to differences in phenotypic variation. For instance, warm-blooded animals tend to have larger bodies in cooler climates closer to the poles, allowing them to conserve heat. This is an example of a latitudinal cline, which is a type of geographic variation.