Genetic variation<span> occurs </span>mainly<span> through DNA mutation, gene flow (movement of genes from one population to another) and sexual reproduction</span>
Explanation: Sexual reproduction is the process that adds genetic diversity to the organism.
The combination of chromosomes that is formed due to combination of male and female gamete gives rise to new characters. This adds diversity in the population of species.
This diversity helps in the process known as the natural selection.
