In a random mating population in equilibrium, random drift brings about a change in gene frequency in a non-directional manner. Random drift is a non-directional factor. In actual practice, the gene frequencies due to random drift may approach to limits, i.e., 0 and 1. This would be possible only when new population arises due to a very small sample leading to the fixation of one allele at the cost of other. In this manner the changes in the gene frequency can be brought about without the existence of any directional force i.e. mutation, selection and migration and this change in gene frequency has been called random genetic drift.