Choosing a partner in a close circle: In the ancient cultures of the Minoans and Mycenaeans, marriages between cousins and first cousins were surprisingly common, researchers report. This is shown by genetic traces in the genomes of numerous individuals who lived in Crete, mainland Greece and the Aegean islands during the Bronze Age.
Modern genetics has found its way into many areas of research - including archaeology: by examining the remains of genetic material, which can sometimes still be elicited from human finds, conclusions can be drawn at various levels: the development history of entire populations can be identified at a higher level. But the individual family backgrounds of people can also be reflected in the genome. The current study by the international research team led by Eirini Skourtanioti from the Max Planck Institute (MPI EVA) for Evolutionary Anthropology in Leipzig now provides information on both levels.
The ancient Aegean reflected in genetics
For the study, the scientists analyzed fossil DNA from a total of 102 people who lived in the Aegean and Crete from the Neolithic to the Iron Age. Some therefore came from the Minoan culture, others from the Mycenaean and the oldest can be assigned to their Neolithic predecessor cultures. As the researchers emphasize, only recent methodological advances have made it possible to obtain extensive data even in regions with climate-related problematic DNA preservation, such as Greece.
First, the team report genetic clues that shed light on population trends in the region over the study period. Thus, early farmers in the Aegean, including Crete, shared a common ancestry. At the end of the Neolithic Age and the early Bronze Age, genetic changes became apparent, which were predominantly of Anatolian origin, especially on Crete. In the Middle Bronze Age, mainland Greece apparently experienced an increased influx of Central and Eastern European people. Their genetic characteristics then reached from the 17th century BC. The researchers report that Crete is also increasingly present.
Frequent cousin-cousin marriages
The study also provided information about the individual genetic backgrounds of the people. In the case of a Mycenaean family whose members were buried in a communal grave, the researchers even managed to reconstruct a detailed family tree. The most surprising result, however, was the evidence of marriage practices in Minoan Crete and Mycenaean Greece: the genetic characteristics of the people reflected that it was common in both cultures around 4000 years ago to marry close relatives. In concrete terms, these were probably connections between cousins and first cousins.
Corresponding genetic patterns are evident in more than 30 percent of the individuals examined, the researchers report. On some islands, about half of the connections seem to have been made in the immediate circle of relatives. “More than a thousand ancient genomes from various regions of the world have now been published, but nowhere else in antiquity does such a strict system of relative marriage seem to have existed. This came as a complete surprise to all of us and raises many questions,” says Skourtanioti.
A lack of partners was probably not the main reason for this form of so-called endogamy, because the genetic data also shows that the populations were probably not critically small, say the researchers. How these special marriage practices can be explained remains speculative: “Perhaps this was intended to prevent the inherited farmland from being divided further and further. In any case, it guaranteed a certain continuity of the family in one place, which is an important prerequisite for the cultivation of olives and wine," says senior author Philipp Stockhammer from the MPI EVA. In conclusion, Skourtanioti says: "What is certain is that the analysis of ancient genomes will continue to provide us with fantastic new insights into ancient family structures in the future."
Source: Max Planck Institute for Evolutionary Anthropology, Article: Nature Ecology & Evolution, doi: 10.1038/s41559-022-01952-3