Finger prints are an example of genetic variation since there is not a set of the same finger prints. Everybody has their own specific pattern to their finger prints.
Human Genetic Variation
Human genetic variation is the genetic differences both within and among populations. No two humans are genetically identical, not even twins are exactly identical.
Without genetic variation, some of the basic mechanisms of evolutionary change cannot operate. There are three primary sources of genetic variation; mutations, gene flow, and sex