Gene Flow

The transfer of genes from one population to another is called gene flow.

For eg., pollen moving from one place to another by the action of wind or people moving to different cities or countries. When a person from one country moves to the other and mates with a person there, a transfer of genes occurs between the individuals. This is how the gene flows between different populations. Gene transfer can be horizontal, i.e., the transfer of genetic material from one population to another by asexual means. This phenomenon is prevalent in prokaryotes.