Lähisukulaisparittelun

Lähisukulaisparittelu, also known as incestuous mating or inbreeding, refers to the mating of closely related individuals within a population. This includes mating between parents and offspring, siblings, or other close relatives such as first cousins. In many species, including humans, there are strong biological and social deterrents to such mating.

The primary biological consequence of inbreeding is an increase in homozygosity. This means that offspring are more likely to inherit two identical copies of a gene, one from each parent. While this can sometimes bring beneficial traits to the forefront if the parents carry desirable recessive genes, it more commonly leads to the expression of harmful recessive alleles. This phenomenon is known as inbreeding depression, where the fitness of offspring can be reduced due to the increased probability of inheriting detrimental genetic conditions. These conditions can manifest as reduced fertility, increased susceptibility to diseases, developmental abnormalities, and lower survival rates.

In human societies, incest is almost universally taboo and often legally prohibited. These prohibitions stem from a combination of biological concerns regarding inbreeding depression and social and cultural factors. The cultural norms surrounding incest vary, but the general consensus across most societies is that it is harmful and undesirable. The degree of relatedness that constitutes prohibited incest can differ between cultures and legal systems.