Allelic variation refers to the differences in the DNA sequence of a particular gene among individuals within a population. These variations, known as alleles, can lead to different traits or characteristics, such as eye color or disease susceptibility. Allelic variation is a key factor in genetic diversity, allowing populations to adapt to changing environments. This variation arises from mutations, which are changes in the DNA sequence. Some alleles may be dominant, meaning they can mask the effects of other alleles, while others are recessive. Understanding allelic variation is essential in fields like genetics and evolutionary biology, as it helps explain how traits are inherited and how species evolve over time.