What is the term for differences in characteristics among individual members of a species?

The term that refers to differences in characteristics among individual members of a species is variation. This concept is fundamental in biology, particularly in the context of evolution and natural selection. Variation can encompass a wide range of traits, including physical characteristics, behaviors, and physiological processes. It is essential for the process of evolution, as it provides the raw material on which natural selection can act. Without variation, a population would lack the diversity needed to adapt to changing environments or challenges.

Homogeneity pertains to uniformity or sameness, which is the opposite of variation. Stability refers to the consistency of a population's characteristics over time, rather than their differences. Mutation, while it can introduce new traits and contribute to variation, specifically refers to changes in the DNA sequence and is just one mechanism that can lead to variation within a species. Thus, variation encapsulates the broader concept of the diverse traits found within a species.