How is diversity in a population created?

Gene flow, often by migration, is the movement of genetic material (for example by pollen in the wind, or the migration of a bird). Gene flow can introduce novel alleles to a population. These alleles can be integrated into the population, thus increasing genetic diversity.

I don't know what type of diversity, but I know genetic diversity

Explanation:

genetic diversity is controlled by 4 processes. mutation, drift, migration and selection. each of them have a analogue at the level of species. speciation creates new species much as mutation creates new alleles