How is diversity in a population created?

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

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.

Explanation:

yes, because even though a theory has a  lot of evidence to support it, it is not always true