The process that allows unique adaptations to persist within a population is termed natural selection. This evolutionary mechanism, proposed by Charles Darwin, suggests that individuals with traits better suited to their environment are more likely to survive and reproduce. Over generations, these advantageous traits become more common within the population. Factors such as competition, predation, and environmental changes drive natural selection, leading to adaptations that enhance an organism's fit to its surroundings. This process is fundamental to the theory of evolution.