Genetic Drift In Different Population Sizes Under Selection

The factors affecting long term selection results were studied in simulated data by GENESYS program, considering two heritability values, two population sizes, 20 generations and three levels of replications in three different populations: random mating, individual selection and BLUP selection. For the two sizes of populations studied and low heritability trait (h(2) = 0, 10), BLUP selection showed greater selection response. Selection response for individual selection considering large population size was similar to BLUP selection response for small population size. Genetic drift was greater for populations on BLUP selection. These results were more evident for small population size and low heritability traits due to the higher inbreeding rate and the percentage of unfavorably fixation.