Answer:
Four conditions are needed for natural selection to occur: reproduction, heredity, variation in fitness or organisms, variation in individual characters among members of the population. If they are met, natural selection automatically results.
Step-by-step explanation:
Evolution, in genetic terms, involves a change in the frequency of alleles in a population over time. What are the sources of genetic variation? Three sources of genetic variation are mutation, genetic recombination during sexual reproduction and lateral gene transfer.