What is all necessary for natural selection to occur?

Necessary for natural selection:

It is the process in the evolution. It explains the nature and it is responsible for the evolution of adoption in the organisms to their environment. The four types of the natural selection are reproduction, heredity, variation in fitness and the variation in the individual characters among the member in the population.

It is the important factor to analysis the environment and reproduction of the organisms. The offspring are resemble same as their parent in the natural selection.