Inbreeding (consanguinity) is a very taboo topic, but regardless, it happens – even in the U.S.
This is when family members who are close relatives produce offspring together, a situation that can lead to a myriad of complications.
Speaking of which, what is the most inbred state of the U.S.?
Kentucky! As a result of inbreeding in eastern Kentucky, the locality is awash with the myth that all families there are inbred.
Eastern Kentucky has the highest inbreeding rates of any section of the state.
Despite increasing diversity and the ability to travel to and from almost anywhere, some communities and families remain isolated, some on purpose, others through poverty.
Table of Contents
- Why is inbreeding common in Kentucky?
- What is the reason for inbreeding in general?
- Is inbreeding permitted in the U.S.?
- Are there any families well-known for inbreeding?
- Which states have the highest rates of inbreeding?
- Are first cousin marriages viewed differently than incest?
- Are first cousin marriages legal in the United States?
- What are the negative consequences of inbreeding?
- Do rates of childhood defects increase due to inbreeding?
- Do lower levels of inbreeding result in fewer diseases?
- How is heterozygosity beneficial to the study of inbreeding?
- What is the historical significance of inbreeding?
- What degree of inbreeding is considered impermissible?
- Does inbreeding harm everyone involved?
- How has the development of infrastructure helped to prevent inbreeding?
- What is the connection between inbreeding and power?
- What other examples of inbreeding are there from before the 20th century?
Many people have relocated to eastern Kentucky’s mountains because of the inexpensive living costs and high quality of life they offer.
Despite this, many areas are still populated mainly by families that have been living there for generations. Inbreeding is a common practice among families that come to the area, either because they lack the money to leave or because they simply don’t want to go.
It appears that in many cases there are no alternative possibilities. A societal taboo in many cultures, the practice of interbreeding (called “incest”) has become accepted by others.
Inbreeding occurs because of a variety of causes:
- Nature’s technique of keeping rare genes and encouraging desirable traits to preserve desired qualities
- These features can be passed on through the generations
- Low-reproduction plants and animals are prone to inbreeding, which is why they must maintain a small population to prevent genetic drift
- For the sake of preserving the ancestry’s original purity, inbreeding is more common in small, isolated human communities than in larger one’s
As a result, small groups that aren’t routinely visited by outsiders are more prone to inbreeding.
In many countries, inbreeding is commonplace. In many civilizations around the world, inbreeding is still common.
Incest is a criminal offense in most states, and it is forbidden in some jurisdictions as well.
It’s legal in some areas, but it’s considered a social sin across the country.
First-cousin marriage is legal in 19 states, though it is not widely practiced. In addition, seven states allow some form of first-cousin marriage.
In the United States, about 0.2 percent of all marriages occur between second cousins or close family members.
This equates to approximately 250,000 people in the United States.
The Fugates are a well-known inbreeding family in Kentucky. For nearly two centuries, the Fugate family was secluded from the rest of society.
When they were inbred, recessive genes passed down from generation to generation, including one that caused some of their kid’s blue skin.
When both parents are genetic carriers of the blue skin gene, the offspring will have blue skin.
As a result of the inbreeding, the recessive gene manifested itself in both parents of the child.
As a general rule, inbreeding is more prevalent in rural and less populated areas of the United States’ Southeast.
About 70% of inbred households reside in rural areas.
Inbreeding is the most common in the following states:
- West Virginia
- North Carolina
- South Carolina
- South Dakota
- New Mexico
This is a delicate subject that may necessitate a bit of further explanation. One of the most common types of familial marriage is the union of first cousins.
The practice of marrying one’s first cousin in the South has become commonplace in the United States.
About a quarter-million people in the United States have married a first cousin.
As a society, we need to know what the law says about marriage and inbreeding.
States’ laws on cousin marriage vary:
- First-cousin marriages are banned in 24 states
- 19 states permit marriages between first cousins
- There are only a few restrictions on first-cousin marriage in the seven states that allow it
- Seven prohibits marriages between first cousins once removed
- Marriage between first cousins is permitted in the US provided both parties are at least 18 years old, and both can consent to their union
Marriages between first and second cousins are generally not recognized in the majority of states unless the couple comes from one of the select few that allow for first cousin wedlock.
Only distant relatives are normally allowed to participate in these types of unions.
Child abuse and long-term trauma can result from inbreeding.
In addition, children born to inbred parents have a higher risk of passing on a hereditary condition.
Homozygous recessive mutations appear to play a role in inbreeding depression, which has been extensively studied.
Inbreeding depression isn’t caused by a single gene; rather, it’s the result of multiple causes working together.
Approximately 20–35 percent of the children born from first-degree consanguineous marriages – whether between brothers and sisters, fathers and daughters, or mothers and sons – have been found to have higher mortality and significant birth abnormalities.
Many of these negative outcomes may be due to nongenetic factors, such as a young mother’s age.
First-cousin children have a mortality rate that is 3.5 to 4.5 percent higher than nonconsanguineous children, and there is an additional 2 to 3 percent of birth abnormalities.
There are fewer deaths and defects at the lower degrees of inbreeding. Consanguineous unions are uncommon in Western populations because of the rarity of the causative genes.
As a result, inbreeding has a smaller impact.
Recessive alleles have the potential to cause future fatalities from inherited disease even when they are present in heterozygous form and have no effect on the person who carries them.
Recessive illness genes are less likely to be passed on to future generations when the offspring of consanguineous parents die as infants.
Recessive alleles can be eliminated from domestic animal stock using the purposeful inbreeding approach.
Some degree of allele heterozygosity would appear to be beneficial, even in highly inbred “pure” lines, as health issues do exist.
Isolation and inbreeding interspersed with outbreeding appear to be the way that many species, including humans, have been established.
The Egyptian dynasties of the 18th and 19th centuries, the Hawaiian ruling elites, the Inca Empire, and Zoroastrian Iran all practiced first-degree consanguineous marriage.
In contrast, incest is a taboo in every society in modern-day. These are statutes and legislation that forbid weddings or sexual relations, or both, among closely related individuals.
Those relatives invariably comprise several inbred groups, and one argument underlying the adoption of incest legislation assumes people’s awareness of negative inbreeding effects on the successors of close-kin partnerships.
The level of inbreeding that is considered impermissible varies widely from society to society, and taboos might extend to nonconsanguineous pairings as well.
Traditionally in China, a guy may marry the daughter of his mother’s brother, but a man and a woman of the same surname cannot marry.
Other explanations for the emergence of incest include an examination of its impact on the family’s economic and educational stability, as well as theories that attribute the diverse definitions of incest to social and psychological factors.
Does inbreeding harm everyone involved?
Although inbreeding has been often regarded as detrimental, the truth is that it doesn’t always cause harm.
A population can suffer from inbreeding, although this can be mitigated by the evolution of genetic processes.
Inbreeding: What Studies Reveal
Four hundred thousand European-born people born between 1938 and 1967 were studied by University of Queensland researchers.
It was found that of those 125 people, at least one parent was a first- or second-degree relation of the other (aunts, uncles, etc.).
Common health difficulties in this group included decreasing cognitive capacities and physical function as well as the lower height and lung function and an increased risk of catching diseases in general.
People are less likely to marry someone they know because of the introduction of modern transportation.
Closed communities such as religious sects, ethnic groups with strong social ties like the Amish or Mennonites, and immigrant populations are the most common places where inbreeding occurs today.
There are greater opportunities for inter-marriage in larger societies.
In the past, inbreeding wasn’t just used to preserve genetic features; it was also used to preserve authority.
To prevent another family from marrying into the line of succession, inbreeding was used in hereditary systems of power, such as the pharaohs of Ancient Egypt.
An Egyptian mummy study conducted in 2015 indicated that royal males were constantly taller than normal, while royal females were consistently shorter than usual.
His mother was his dad’s niece, and his grandmother was also his aunt, so the family tree was rather muddled at this time.
Charles was born with a slew of physical and mental impairments. He couldn’t walk until he was eight years old, and his malformed jaw made it difficult for him to even chew.
Autopsy reports on the death of this man are harrowing.
When he was dead, Charles had a heart the size of a peppercorn, corrosion-stained lungs, water-filled brain, and a single testicle as black as coal.
Assuming that the pituitary hormone deficit and distal renal tubular acidosis aren’t to blame for all of these illnesses, both are recessive alleles.