Which process describes variability within a population that arises from genetic differences?

The correct choice, genetic variation, refers to the diversity in gene frequencies within a population. This variability is the result of genetic differences among individuals, which can be attributed to mutations, gene reshuffling during reproduction, and other genetic mechanisms. Genetic variation is crucial for evolution and adaptation, as it provides the raw material upon which natural selection acts. Without genetic variation, a population would have reduced adaptability to changing environments, making it more vulnerable to extinction due to diseases or environmental shifts.

Natural selection involves the process by which individuals with favorable traits are more likely to survive and reproduce; however, it relies on the presence of genetic variation in the population to select favorable traits. Environmental adaptation refers to the way organisms adjust to their surroundings, which may be influenced by genetic variation but does not directly describe the source of that variability. Reproductive isolation is a mechanism that prevents different species from interbreeding and does not directly address genetic variability within a population. Overall, genetic variation encapsulates the essence of genetic differences contributing to diversity within populations.