Question

How does natural selection support the theory of evolution?

Answer 1

Natural selection is generally one of the central and important mechanisms of evolutionary change & is a process which is responsible for the evolution of the adaptive features. Without a basic and working knowledge of the natural selection, it is generally impossible to understand how or why the living things exhibit their diversity & inherent complexity.

Complete answer:
Natural selection is generally a non-random difference in the reproductive output among the replicating entities, often due indirectly to the differences in survival in a particular environment or condition, leading to an increase in the proportion of the beneficial, heritable characteristics within the population from one generation to the next one.
By evolution , it is probable that the reference is to the Darwinian or Neo Darwinian evolution theory.
Darwinian evolution normally attempts to explain the origin of all life forms by the natural causes. One of these natural causes is called natural selection.
Natural selection will explain how different forms of animals can arise from the environmental changes and natural variations.
A classic textbook example of this is the peppered moth in England. The changes in the environment which is seen during the industrial revolution made the black or metallic form of peppered moth to be selected over other forms of the peppered.
Natural selection also provides evidence of the changes within the species or type of the organism. Such as the 13 different types of finches on Galapagos Islands.

Note: Natural selection provides evidence of changes within the species that supports the idea of larger changes between species by the extrapolation. This is an indirect form of evidence for Darwin's theory of the Descent through modification.