Evolution, theory in biology postulating that the various types of living things on Earth have their origin in other preexisting types and that the distinguishable differences are due to modifications in successive generations.
Evolution, as related to genomics, refers to the process by which living organisms change over time through changes in the genome. Such evolutionary changes result from mutations that produce genomic variation, giving rise to individuals whose biological functions or physical traits are altered.Evolution can be seen as a two-step process. First, hereditary variation takes place; second, selection is made of those genetic variants that will be passed on most effectively to the following generations.