What is the role of hereditary variability in the evolutionary process?

Hereditary variation is the basis for the diversity of individual differences. The types of hereditary changes are the material of the evolutionary process. Each new generation leaves for itself the necessary and useful signs, adjusted by the conditions of the environment and habitat. Thus, hereditary variability is the ability of organisms to acquire and fix new traits in the genotype, which are inherited and do not disappear when living conditions change.