Inbreeding

Inbreeding is the sexual reproduction of offspring from the mating or breeding of individuals or organisms that are closely related genetically. 

This type of mating which leads to inbreeding is known as “incest“.

By analogy, the term is used in human reproduction, but more commonly refers to the genetic disorders and other consequences that arise from incestuous sexual relationships and consanguinity.

Inbreeding can lead to weak borne structure, physical and mental disabilities. 

Inbreeding results in homozygosity, which can increase the chances of offspring being affected by recessive or deleterious traits.

This generally leads to a decreased biological fitness of a population (called inbreeding depression), which is its ability to survive and reproduce.

An individual who inherits such deleterious traits is referred to as inbred. 

The avoidance of such deleterious recessive alleles caused by inbreeding, via inbreeding avoidance mechanisms, is the main selective reason for outcrossing.

Crossbreeding between populations also often has positive effects on fitness-related traits.

Offspring of biologically related persons are subject to the possible effect of inbreeding, such as congenital birth defects.

The chances of such disorders is increased the closer the relationship of the biological parents. (See coefficient of inbreeding.) 

In the short term, incestuous reproduction is expected to produce increases in spontaneous abortions of zygotes, perinatal deaths, and postnatal offspring with birth defects.

This also means that the closer two persons are related, the more severe are the biological costs of inbreeding.

There may also be other deleterious effects besides those caused by recessive diseases. Thus, similar immune systems may be more vulnerable to infectious diseases.

This is because such pairings have a 25% probability of producing homozygous zygotes in the offspring, containing 2 recessive alleles, which produce disorder.

There are several methods to compute this percentage. The percentage in which inbreeding (giving of birth to disorderly offspring) is likely to occur.

Typical coancestries between relatives are as follows:

2016-01-28 10:55:58