How does natural selection contribute to evolution?

Natural selection plays a crucial role in evolution by favoring individuals with traits that provide a survival or reproductive advantage in a given environment. This process leads to the gradual accumulation of advantageous traits within a population over successive generations. As individuals with these favorable traits are more likely to survive and reproduce, they pass these traits on to their offspring, which can eventually result in significant changes in the population's genetic makeup.

This mechanism is not about random changes; instead, it is selective, meaning it actively promotes the propagation of beneficial traits while disadvantaging those that are less suitable for survival in the specific environmental context. As such, natural selection shapes the evolution of species by enabling them to adapt to their surroundings, enhancing their overall fitness in the evolutionary sense.

In contrast, other choices do not accurately reflect the principles of natural selection. For example, random changes in allele frequencies typically refer to genetic drift, not natural selection. Immediate changes in genetic makeup do not occur due to natural selection; instead, changes happen over long periods, as favorable traits become more common. Lastly, natural selection does not guarantee that all individuals in a population will reproduce successfully, as success in reproduction is contingent on having advantageous traits that are suited for the particular environment.