Inbreeding is defined as the formation of offspring which results from the mating of two closely related organisms
Inbreeding affects allele frequencies and genotype frequencies in a population in following ways:
Inbreeding increases homozygosity
which in turn decreases the biological fitness of a population because there are chances that offsprings will be affected by deleterious traits in this case
Inbreeding itself does not cause evolution, because allele frequencies do not change in the population as a whole
