Gene flow

Gene flow (also known as gene migration) istransfergenes from one populationanother.

Migration into or out ofpopulation may be responsible formarked changegene pool frequencies (the numberindividual members withparticular trait). Immigration may result inadditionnew genetic material toestablished gene pool ofparticular species or population,conversely emigration results inremovalgenetic material.

Gene flownot absolute, however, andidea that desirableundesirable traitscompletely under genetic control—an idea that gave birth toeugenics movements inUnited States inearly 1900s,in Nazi Germany in1930s—is demonstrably incorrect.

It has been demonstrated thatGreat WallChina has hinderednatural flowplant genes. Examples ofsame species which grow on either side have been shownbe genetically different.

There arenumberfactors that affectrategene flow between different populations. One ofmost significant factorsmobility,animals tendbe more mobile than plants. Greater mobilityan individual tendsgivegreater migratory potential.

Although thereno documentary evidencegene flowhumans,it has only been demonstratedinsect populations, genes can flow between species, as when bacterial DNAtransferredanimals or plants.