Expanded genetic study reveals mating customs of mysterious Avar knights

An analysis of hundreds of burials in the region of Hungary reveals the longest known family tree – and the absence of daughters in the Avar knightly culture.

In 568 AD, according to contemporary records, warrior knights of the Mongolian steppes, called Avarsinvaded the grassy plains flanking the Danube River, more or less in the territory of modern Hungary.

Together with other Central Asian groups, they formed a new center of power in Europe, forcing the Byzantine Empire to pay tribute. But they left no written record.

Now, using DNA samples collected from hundreds of burial sites, including entire Avar cemeteriesa team of researchers has filled in some of the gaps that existed in our knowledge of the culture of these mysterious knights.

Published this Wednesday in the magazine Naturethe study, which includes the longest DNA-based family tree ever published, spanning nine generations, used kinship data to reconstruct the Avar mating patternsits mobility and even local politics.

The study is the greatest example of a new trend in ancient DNA research: studying not only isolated individuals, but entire communities and families — as is the case that ZAP recently reported on the study of the family of Alíria Rosa, the Colombian woman who escaped Alzheimer’s.

“The idea of ​​creating the entire cemetery is fantastic,” he tells Science Florin Short, a historian at the University of Florida who was not involved in the investigation. “It’s a way of write history in the absence of written sources“.

Ancient DNA from Avar bones had already helped clarify the question of origin of this nomadic people.

In a previous study, researchers showed that many Avars buried in Hungary around 600 AD shared ancestry with people buried in Mongolia just a few decades earlier, implying a long-distance migration that covered more than 7000 kilometers in the space of a generation.

But other questions remainedsuch as the way the Avars organized their society and adapted their customs to their new home.

To find out more, the team of geneticists, archaeologists and historians sequenced the DNA of more than 400 skeletons from four cemeteries located within a radius of 200 kilometers; radiocarbon dating showed that burials spanned the 250 years of Avar rule in the region.

The team then looked for first or second degree relationships: mothers and children, brothers and sisters, aunts and uncles. The cemetery-wide approach made it possible to reconstruct entire family treessome containing dozens of individuals.

The complete tree, spanning nine generations, extended from one man founder buried shortly after arrival from the Avars to a descendant buried 250 years later.

“The community approach made these people really come to life for me,” he says Zsófia Ráczarchaeologist at Eötvös Lorán University and co-author of the study.

“We detected that he excavated one of the sites. their communities – it is something that we would never have seen through written sources or archeology alone”, explains the researcher, who participated in the excavations of one of the cemeteries.

DNA also showed that the Avars buried people with close family ties togetherin what could be considered as family plots.

“At a cultural level, this shows that biological kinship was important in this society, and suggests that Avar society emphasized biological affiliation”, says Zuzana Hofmanovágeneticist at the Max Planck Institute for Evolutionary Anthropology and also the co-author of the study.

All men in the study descended from a small number of men adults, buried with rich objectswho are supposed to be the founders of the community.

But “all adult females are external and have no fathers in the cemetery”, says the geneticist Guido Gnecchi-Ruscone, also a Max Planck researcher, who led the effort to reconstruct family trees. Instead, women tend to have distant relatives in other cemeteries.

This pattern corresponds to a practice that ethnographers call patrilocalityin which men remain in place while women leave their place of birth to find a partners, a pattern also observed in ancient European farmers, among others.

DNA also revealed polygamy and “levirate unions,” in which closely related men – brothers, or father and son – had children with the same woman.

This pattern was “archaeologically invisible, but thanks to genetic data we could clearly see the role of women”, he says Tivadar Vida, archaeologist at Eötvös Loránd and co-author of the new paper. “Women were linked to different communities.”

The strict patrilineal system and marriages with non-local women appear to have helped the Avar to avoid inbreeding: After analyzing the DNA of hundreds of people, the team found no examples of children born to close relatives or even to people separated by up to five degrees.

It is likely that the oral tradition helped the Avars to maintain correct blood lines over the centuries, preventing marriages with distant cousins. “We don’t know much about the Avar languagebut we seem to know one of the things they communicated about,” says Hofmanová.

The researchers even found andevidence of political changes in DNA data. In one of the cemeteries, several generations of closely related men were buried close to each other. Then, after 650 AD, there are no longer any descendants of the original male line buried in the cemetery.

Thus, apparently a new male lineage marries and their descendants are buried about 100 meters aways away, without the horses that normally accompanied men in previous graves, which indicates a cultural change.

Perhaps a local clan has lost favor after a change in leadership, for example. But the rupture is not complete: the two parts of the cemetery, and the long family tree, are therelinked by maternal half-siblingss. “The connection is made through a woman,” says Hofmanová.

The Avars maintained their social practices even when other aspects of their society have changed drastically.

For example, based on radiocarbon dating and changes in settlement and burial patterns, archaeologists know that about 50 years after arriving in Europe, when suffered a resounding defeat At the hands of the Byzantine Empire, the Avars abandoned their nomadic lifestyle, settled in villages and cultivated cereals.

But DNA shows that their patrilocal traditions persisted. “Despite having established themselves, they maintained their traditions of social organization,” says Rácz.