6. King Tut’s mother and father were brother and sister, which resulted in an abnormally curved spine, flat feet, and toes missing on his right foot.
King Tut’s father, Akhenaten, and his mother were brother and sister, and he himself married his half-sister, Ankhesenamun. He suffered from necrosis of the bone in his left foot causing him to have to use a cane to walk. It is speculated that he also suffered from a crippling bone disease. According to National Geographic, his immune system could have been severely compromised because of multiple malarial infections which interfered with the healing of his foot. These maladies, along with a fracture found in his left thighbone, could have been the reason for his death.(source)
7. Consensual adult incest is legal in France.
Different countries and jurisdictions react differently to incest. Some countries believe that consenting adults should be free to have sex, some others believe that they should not be related in certain ways, while some allow sex but not marriage. New Jersey is one of the jurisdictions that does not apply any penalties when the people involved are 18 years or older. Countries that allow incestuous relations between consenting adults are Netherlands, France, Slovenia, Spain, the Benelux and Portugal.(source)
8. Unlike most species, bedbugs thrive on inbreeding. Along with resistance to insecticides, inbreeding has caused their population to grow by 500 percent.
Mating is dependent on a species’ ability to find a partner. If the species is cut off from a genetically diverse partner because of its isolated location or for any other reason, inbreeding is bound to occur. The same was true with some colonizing species such as bedbugs which have become resistant to inbreeding depression as they cannot easily reach other populations that are far away. “Inbreeding depression” is the extinction of the inbreeding population due to the deleterious effects of mutations. However, as the bedbugs cannot fly, they have evolved the ability to withstand extensive inbreeding without deleterious effects.(source)
9. There is a family in Kentucky called the “Blue Fugates”, so named because of their blue skin caused by methemoglobinemia, a rare genetic condition, that they inherited as a result of inbreeding.
Around 1820, a man named Martin Fugate settled near Hazard, Kentucky. As their settlement is a remote rural area, his family and the other families there intermarried. Martin Fugate’s wife, Elizabeth Smith, was a carrier of methemoglobinemia, so was the family that the Fugates intermarried with. This resulted in their descendants inheriting the gene that caused blue skin. During the 20th century, nurse Ruth Pendergrass and hematologist Madison Cawein III studied the condition. Cawein treated the family with methylene blue, which reduced their symptoms and blue color. Benjamin Stacy, born in 1975, was the last known descendant wth the gene as the family began to spread out with better access to travel.(source)
10. Charles II of Spain, a descendant of many generations of inbreeding, was physically and mentally disabled, and also infertile. He could barely chew, couldn’t speak until he was four, couldn’t walk until he was eight, and with his death, the line of Spanish Habsburg died.
Charles II of Spain was born in 1661 in Madrid to King Philip IV of Spain. Since approximately 1550, outbreeding in Charles II’s lineage had stopped causing all his ancestors to be the descendants of Joanna and Philip I of Castile. First-cousin and uncle-niece marriages were common in 17th-century European nobility. His mother, Mariana of Austria, a Habsburg too, was the niece of his father. The inbreeding was so extensive that his genome was more homozygous than that of someone born to siblings. He was born disfigured, with a tongue so large he could barely chew and often drooled. He married twice without being able to produce an heir. He was the last Habsburg King of Spain and his death in 1700 started the War of Spanish Succession which lasted for 13 years.(source)