Answer:
natural selection is one mechanism by which evolution occurs
Step-by-step explanation:
One of the driving mechanisms for evolution to occur is Natural selection. it is how nature used selection pressure( environmental factors) in the surrounding environments of the organism to select or favour the fittest organisms, against the less fitted, with increases gene flow, and therefore population as the fitted organisms, with subsequent increase in the offspring population.
Natural selection is driven by mutation which causes variation. These interrelated forces altered the Genotypes of fitted organisms, and therefore made them to have selected advantages over the less fitted ones.With period of time the population of the less fitted fizzled out, while the fitted organism population evolved to dominate the environments.