Final answer:
Genetic drift impacts allele frequencies due to random chance events, particularly in small populations, potentially leading to significant changes in the population's genome. It can cause alleles to become more or less common or even fixed through chance events rather than by providing survival or reproductive advantages.
Step-by-step explanation:
Genetic drift impacts the frequency of alleles in populations, leading them to become more or less common or fixed through C) due to random chance events in small populations. This process occurs when alleles in an offspring generation are a random sample of the alleles in the parent generation. Due to chance, some alleles may not make it into the next generation, which can significantly alter allele frequencies, especially in small populations. For instance, if one individual carrying a unique allele dies before reproducing in a small population, all of its alleles could be suddenly lost. Conversely, in larger populations, the impact of losing a single individual's alleles is less pronounced.
Genetic drift and natural selection often occur simultaneously, but genetic drift is not a deliberate process nor does it favor specific alleles for their advantages. It can, however, lead to significant changes in a population's genome and even result in alleles becoming fixed purely by chance. This contrast with natural selection, which promotes alleles that confer survival or reproductive advantages.
The Hardy-Weinberg Principle assumes a population in genetic equilibrium that is not experiencing genetic drift, among other factors. Hence, in a real-world scenario, genetic drift can cause actual allele frequencies to deviate from the frequencies predicted by the Hardy-Weinberg equilibrium.