What is the characteristic of natural selection regarding allele frequencies?

Natural selection is a key mechanism of evolution that acts on the phenotypic variations within a population. It is characterized by differential survival and reproductive success of individuals based on their traits. The essence of natural selection is that individuals with advantageous traits are more likely to survive and reproduce, thereby passing those favorable alleles to the next generation. This process leads to changes in allele frequencies within a population over time.

When certain alleles confer a survival or reproductive advantage, these alleles tend to increase in frequency because the individuals that possess them are more successful in reproducing. Conversely, alleles that are associated with less favorable traits may decrease in frequency as those individuals tend not to survive or reproduce as successfully. This dynamic illustrates how natural selection directly impacts the genetic makeup of a population by favoring specific alleles based on their contribution to fitness, ultimately leading to evolution.

Thus, the correct choice highlights that natural selection can indeed change allele frequencies in a population depending on the reproductive success of individuals carrying certain alleles. This understanding is crucial when studying genetics and evolutionary biology, as it emphasizes the role of natural selection as a driving force behind genetic variation and adaptation.