Simulation of genetic drift in closed population under different initial gene frequencies.

Computer simulation was used to determine the random genetic drifts of a biallelic gene locus in closed populations under different initial gene frequencies,population sizes and male-female ratios,based on the assumption that there was no gene mutation and individual immigration between populations.Random selection and mating were implemented in all generations,the generation was non-overlapping and the number of breeding animals was kept equal in each generation.The simulation experiment was carried out for 50 generations and 100 replications.The results showed that the smaller random fluctuation of gene frequency,the lower probability of gene loss or fixation resulted from random genetic drift were gained for larger size population,more males and medium level of initial gene frequency.The danger of gene loss or fixation would be increased for smaller population,fewer males and lower or higher initial gene frequency.