Which statement characterizes the impact of natural selection on a population?

Natural selection plays a crucial role in shaping the traits of populations over time. The correct statement indicates that natural selection increases variations that enhance survival and reproduction. This process works by favoring individuals with traits that are better suited to their environment, thus those individuals are more likely to survive and reproduce. Over generations, these beneficial variations become more common within the population, leading to an increase in the overall fitness of the population.

Natural selection does not lead to genetic uniformity and stability, as it encourages diverse traits that allow a population to adapt to changing environments. Additionally, while natural selection can influence competition, it does not eliminate it; rather, it shapes the competitive dynamics by favoring traits that enhance success in acquiring resources. Finally, the process of natural selection is gradual and does not produce immediate changes across all traits. Instead, it results in evolutionary changes over longer periods, reflecting the adaptive responses of the population to its environment.