Genetic and/or environmental differences within a population are called?

• A. Variation
• B. Mutation
• C. Adaptation
• D. Selection

Answer: (A)

Variation describes the differences you see among individuals in a population. These differences come from genetic factors passed down and from environmental influences that can change how traits develop or are expressed. Because of this mix of genetic and environmental differences, some individuals have traits that suit the environment better, which is why variation is essential for evolution and selection to act on.

Mutation is a way new genetic differences can arise, but it’s just one source of variation. Adaptation refers to a trait that helps survival in a given environment, not the overall set of differences itself. Selection is the process that changes how common different traits become over generations, not the existence of those differences.