Final answer:
Inbreeding depression violates Hardy Weinberg's assumption of random mating and leads to a decline in average fitness. It occurs when homozygosity increases and heterozygosity decreases.
Step-by-step explanation:
Inbreeding depression violates Hardy Weinberg's assumption of random mating and is a decline in average fitness in a population that occurs when homozygosity increases and heterozygosity decreases. Inbreeding is the mating of closely related individuals, such as cousins marrying cousins, which leads to an increase in homozygosity. This decrease in genetic variation can result in reduced reproduction and survival, causing inbreeding depression.