Answer: A change in allele frequencies caused by random events
Explanation :Genetic drift refers to a process which occur due to sampling error from preceding generations that lead to a change in allele frequency by chance alone within a population. It is a random process which leads to large significant changes within a population over a short period of time. The rapid changes are due to increasing inbreeding coefficient s and homozygosity from the removal of alleles.
It is peculiar to a population which is synonymous with regular cycle of extinction and recolonization. Therefore, together with evolution, mutation and migration, it is one of the driving mechanism of EVOLUTION.
It is caused by;
Static or recurring small population sizes,
"Bottlenecks” form of population, that is drastic reduction in population size;
Repopulation from a small number of individual-FOUNDER EVENTS.
Measurements of Genetic Drift
The magnitude of genetic drift within a population depends on the effective population size for the population.This is represented as Ne. It is a theoretical number use to quantify the number of genetically distinct individuals that contribute gametes