The phenomenon by which new traits are added to the population due to interbreeding with another group of population is known as gene flow.
The phenomenon of gene flow is also called migration.
In gene flow, the constant migration of individuals in or out of a population takes place.
This affects the composition of the gene pool i.e. the genetic constituent of the population keeps changing and new traits are added to the population.
Assisted gene flow (AGF):
The phenomenon of assisted flow or migration of genes from one population to another population to produce offspring with desired traits or to make the particular species of a population adaptable to the changing environmental conditions is known as assisted gene flow.
AGF is done to accelerate the adaption of plants and animal populations against environmental changes.