Question

Differentiate "Gene flow' and 'Genetic drift'.

Answer 1

GENE FLOW describes the movement of gene alleles from one population into another. A mutation in a gene might arise in one population in one location and then - if that population interbreeds with another population - that new gene can "flow into" the new population.

GENETIC DRIFT is a phenomenon that causes changes in gene frequencies in the absence of any selection pressure. It occurs when population sizes are very small, if the population is small, then it is all pure luck to determine which genes might make it to the next generation or which genes might be lost from the population. Under a genetic drift scenario, the genes just drift around in frequency independent of their fitness value.