For thousands of years, couples have had to decide where to live.

"For the vast majority of human history," said lala cassidy"Society is centered around kinship, so you decide whose family you want to live with," said the geneticist at Trinity College Dublin.

In Britain, during the Neolithic Age (characterized by the introduction of agriculture) and the Bronze Age (c. 4000 to 800 BC), prehistoric human societies tended to be patriarchal. That's "where women move," Cassidy said. "They leave home after they get married and join the village, their husband's community."

That's why Cassidy and her colleagues were surprised to find the remains of a Celtic tribe who lived in Iron Age Britain between 100 BC and 100 AD. After studying their DNA, they found that women were the source of their social network. center. The study was published in nature.

"This is a really rare pattern," Cassidy said. "Never before in European prehistory have so many people been related through female lineage. This is further evidence that women were able to exert considerable social and political influence in these societies."

Challenges women often face

Patriarchy is often a more difficult arrangement for women. "It separates them from their families," Cassidy said. "You lose your childhood support network. You emerge as a relative stranger."

Researchers know that women joined their husbands' communities by examining ancient DNA from groups buried together during the Neolithic and Bronze Ages.

"When most men have the exact same Y chromosome," Cassidy said, "that Y chromosome is passed from father to son, and from father to son, meaning they all descend from the nearest male through the male lineage. Passed down from our ancestors.”

After the Bronze Age, came the Iron Age. In Britain it began around 800 BC, a period during which little is known about the structure of society, although there are indications that at least some British women did have some degree of influence.

"Sometimes, whenever you hear about a female ruler or find a very wealthy tomb, you subconsciously assume that this is an exception or that she must have been the wife of someone important," Cassidy said. It’s not that she is important.”

a special cemetery

Cassidy was eager to collaborate on research on the remains of Iron Age burial sites of the Durotriges, a Celtic tribe that dates from 100 BC to AD 100 in what is now southern England. "It's very unusual for a cemetery to have unburned burials," she said. "Funeral practices in Iron Age Britain appear to have been quite diverse, but there was a lot of cremation and scattering of remains across the landscape. So this is a very unique opportunity to learn about a large number of members of the same community."

Cassidy and her team sequenced ancient DNA from the dense bones surrounding the inner ears of more than 50 individuals.

“When we finished our first batch of sizable samples, we immediately saw on the screen that there was something special about this site,” she recalls.

The males of this community do not share the Y chromosome. Instead, individuals share mitochondrial DNA, which is passed from mother to child.

"That's when I thought, 'Oh my God,'" Cassidy said. "This is a community where a lot of people have female ancestry. It's matrilineal and it's rare. I didn't expect it."

Matriarchy is the opposite of patriarchy - the man leaves the family to live with his wife. The women stayed in their own communities.

"So they were more than just mothers and wives," Cassidy explained. "They are also daughters, sisters and cousins. They are embedded in a wider network of relatives and people they have known since birth. So they have a stronger support system."

This was not a matriarchal society where women necessarily held positions of power, but Cassidy said they had status and influence over family finances, decisions and property.

She and her colleagues found the same thing when they examined hundreds of Iron Age genomes from cemeteries across Britain. "Most of the people buried there are descendants of a handful of women," Cassidy said. "That's when we thought, 'This is common on the island. This could be a custom that goes back centuries.'" ​

"The results are interesting because they show a very, very different picture compared to the rest of Europe," said Marta Cintas PenaPrehistoric archaeologists from the University of Seville were not involved in the study. However, she cautioned that data from this period are poorly documented. “I wouldn’t say that was the case before patriarchy, but things changed after that,” she said. "I think we need more data to confirm or reject this."

language and war

"I was very impressed by this article," said Carol Emberis a cultural anthropologist and chair of the Archives of Human Relations at Yale University, who also was not involved in the study. "But I'm not surprised that matriarchal societies existed in the past."

"That's because, although maternal settlement is not common, it does account for about 15 percent of anthropological records," including in central Africa and some Native American communities, she said.

Amber says there's something interesting about matriarchal societies. They often spoke a different language (in this case, Celtic) than their neighbors - evidence that they may have migrated from somewhere else. "If you successfully invade someone else's territory," she said, "that means you have to be fairly successful in the war."

It turns out that matriarchal societies tend to do well in foreign wars. Amber, Cassidy and others believe this may be due to a lack of internal fighting and broader tribal unity. "It's not certain yet, but it's a good theory," Cassidy said.

Still, much is unknown about this Celtic tribe, as well as the many prehistoric human groups scattered across time and space, but Cassidy believes ancient DNA will help solve some of the mysteries.

"I think there are going to be more surprises," she said, "and we need to keep an open mind as we start to dig deeper."