The oldest archaeological record of incest has been found recently during an excavation at the cave site of Grotta della Monaca in Calabria, Italy. The findings of this excavation were revealed in a genetic study published in the journal Communications Biology.The team of researchers found this clue of incest in the remains of a teenage boy who was buried in southern Italy in a Bronze Age cemetery. The cave site, which is famously called the “toe” of Italy, was used as a burial ground between 1780 and 1380 BC. In their pursuit of understanding the genetic background, the archaeologists analyzed the DNA of the 23 people who were buried there. But what they found shocked them all. They did not anticipate finding such “extreme parental consanguinity.,Published on December 15, the team of researchers outlined their genetic findings from prehistoric Grotta della Monaca. The burial site was a difficult one, as the skeletons were fragmented and mixed up. Even so, the researchers were able to establish the genetic sex of 10 females and eight males. They also identified a wide range of mitochondrial and Y-chromosome DNA haplotypes, genetic markers passed down from parents, suggesting that the group was made up of people from diverse backgrounds.Through their investigations, the researchers found two cases of first-degree relatives, meaning parents and their offspring. At first glance, the findings were not revealing, as cultures have historically practiced burying family members together. They found that a mother and a daughter were buried next to each other at Grotta della Monaca.However, another case involving an adult man and a pre-adolescent male buried in the Grotta della Monaca cave was striking. The researchers ran a test measuring runs of homozygosity (ROH) segments in their DNA to establish their relationship. A low ROH indicates a mixture of genes due to mating outside the biological family, while a higher level of ROH indicates inbreeding.Most of the 23 individuals buried at Grotta della Monaca showed ROH levels indicating their parents were distantly related, likely within the past six to ten generations, the researchers noted. However, one pre-adolescent male stood out, having the highest total of long ROH segments ever recorded in ancient genomic datasets to date.A deeper investigation found “indisputable evidence that the young male was the offspring of a first-degree incestuous union.” This unambiguously indicated that he was the son of an adult male and his daughter. The skeletal remains of the young boy’s mother were not found.Both due to cultural taboo and biological instinct, there is a strong stigma attached to the concept of incest. People rarely talk about or discuss it at length. But this does not mean there have been no archaeological or historical records of incest. Live Science reports that an Altai Neanderthal’s genes suggested her parents were half-siblings. Not only that, in ancient Egypt there were well-documented cases of brother-sister unions. Akhenaten (also known as Amenhotep IV) married his sister Nefertiti, and it was claimed that their parents were also close relatives.However, a sibling union is considered a second-degree union, whereas a parent-child union is considered first-degree—and such unions tend to have higher chances of abnormalities in their offspring.The young boy in question, however, had no genetic disorder. The discovery of a father-and-daughter union producing a son is “an exceptionally rare and remarkable finding,” the researchers wrote, as well as “the earliest identified in the archaeological record.”The reason why the people of Grotta della Monaca engaged in such a practice remains a mystery. The community was neither small nor organized around a hierarchical or royal inheritance system where marrying close kin would strengthen power and wealth.“The reproductive union between parent and offspring observed in our study may reflect a socially sanctioned behavior,” the researchers wrote. The fact that there was only one male buried in a burial site of children and women needs to be explored further. The circumstances of this union remain uncertain.“This exceptional case may indicate culturally specific behaviors in this small community, but its significance ultimately remains uncertain,” study co-author Alissa Mittnik, an archaeogeneticist at the Max Planck Institute for Evolutionary Anthropology in Germany, said in a statement.
