Natural selection causes changes in populations and phenotypes. While individual organisms may exhibit different traits, it is the population as a whole that experiences changes over time. These changes occur as certain individuals with advantageous phenotypes have a higher chance of survival and reproduction, passing on their genes to future generations. This process leads to a gradual shift in the genetic makeup of a population, favoring traits that increase an organism's fitness in their environment. These changes in genotype result in changes in phenotype, as the traits that enhance an organism's survival and reproductive success become more common in the population.
