Natural selection plays a crucial role in evolution by favoring individuals with advantageous traits that enhance their survival and reproductive success. These traits become more common in a population over generations, leading to adaptations that help organisms thrive in their environments. This process results in the gradual evolution of species, as well as the emergence of new species from common ancestors. Additionally, natural selection contributes to the diversity of life forms on Earth, illustrating the complex interplay of genetic variation, competition, and environmental pressures.