Abstract
All populations are finite in size so that genetic drift will occur in all natural and managed populations. Genetic drift causes both changes in allele frequencies and the loss of genetic variation. Loss of heterozygosity and loss of alleles are t^ghe two primary measures of the loss of genetic variation in populations. Matings between related individuals (i.e., inbreeding) is more common in small populations, and this will lead to inbreeding depression in small populations. Understanding the effects of genetic drift is especially important for conservation because loss of genetic variation and inbreeding depression can reduce the probability of population persistence.