Definitions / Explanation : Genetic drift & Gene migration (gene flow)

 

It refers to chance elimination of the genes of certain traits independent of genes useful or harmful effects when a section of population migrates or dies of natural calamity. It alters the gene frequency of the remaining population.

- If the migrating individuals interbreed with the members of local population, these may bring many new alleles into the local pool of the host population. This is called gene migration.

This addition or removal of alleles when individuals enter or leave a population from another locality is called flow.