Inbreeding depression

A inbreeding depression is the reduction of power ( susceptibility to disease at a higher inbreeding coefficient in the population ) of inbred populations. It occurs especially in confined habitats in which the genetic variability of a population is limited, and if necessary there is a genetic bottleneck. This is the case, do not allow any exchange with other islands, among others, with small animal populations on islands of their habitat. In such populations increasingly hereditary diseases can occur, see also endogamous hereditary diseases in populations.

Inbreeding depression may also be a consequence of breeding programs in which always the same special vegetable or parent animals are used for breeding (eg Champion breeding in dogs).

Due to the indivisibility of the genome at the level of individual alleles results in a loss of alleles from the gene pool, the genetic diversity and thus the effective population size reduced gradually. It arises due to the genetic uniformity of the population inbreeding also between non- related couples closer. The population can degenerate and become more susceptible to diseases.

Under certain conditions, inbreeding depression can be overcome with continued inbreeding. This phenomenon is referred to as purging.