Ancient Tombs Reveal 'Valley' and 'Hill' People That Coexisted 5,000 Years Ago

Ancient Spanish tombs that date back over 5,000 years have been found to contain members of two distinct cultural groups, despite being found just miles apart, researchers have said.

Previously, the tombs, in the Rioja Alavesa region, were thought to belong to the same group, with different graves representing people of different social status. But dental analysis has now revealed this is not the case.

At the site, human remains were found either in cave burials or in megalithic graves. The latter would have required considerable effort to build.

In a study published in Science Advances, researchers say the "invested energy" into megalithic tombs is generally linked with "a more privileged segment of the community compared to those in caves."

But the team, led by Teresa Fernández-Crespo, from the U.K.'s University of Oxford, wanted to find out more about the people at the Neolithic site.

"We are always interested in learning more about the lives of people living in the past," co-author Rick Schulting, also from the University of Oxford, told Newsweek.

The researchers decided to look at the remains at the site—both in the cave and megalithic tombs—using teeth to track dietary and lifestyle differences. Stable isotopes locked into a person's teeth over the course of their lives can provide information on their diet and geographic origin that skeletal remains cannot.

"The sequential sampling of teeth allows us to trace back in an individual's life history when this difference first emerges, since the teeth do not change their isotope signals once formed, whereas bone remodels during life," Schulting explained.

Previously the researchers had found evidence to suggest people buried in the megalithic tombs had vastly different diets to those in caves. They were also utilizing different parts of the landscape. With the latest study, the team was hoping to find out if these differences were present from early childhood or if they emerged in later life.

"If the difference only emerged later in life, it could reflect different 'occupations' within single communities using two burial practices—monument and cave. If it is present from early childhood, it is more likely that there were distinct communities using the monument and caves for burial, despite how close together they are."

Their findings showed significant differences from childhood. Children were weaned at different ages, they ate different foods and engaged in different land use practices. The team says that despite living just three miles from one another, there were distinct "valley" and "hill" people, and that the two cultures would have had regular contact.

"Our expectation is that those living in the valley and using the megalithic monuments for burial had access to more secure and abundant food resources, as this holds the better arable land in the region. This would have allowed higher crops yields and so likely supported a large population compared to those living in the hills along the valley margins," Schulting said, adding the valley people, while apparently wealthier, were not necessarily healthier. Their teeth tended to have more cavities, suggesting they ate more carbohydrates.

Living in such close proximity would have led to regular contact, the team says. Schulting said they probably exchanged goods and intermarried, but not to a point where they start looking the same. As there is no evidence of fortifications, they likely coexisted peacefully most of the time, he said.

"But nevertheless the presence of an 'other' within such close proximity may also have meant that at certain times tensions rose and that these did on occasion lead to lethal violence. There is a fair amount of evidence for this in the skeletons from this area, a number of which have embedded arrowheads."

The researchers now hope to look at evidence for violent conflict in the wider region during this period. "It is not possible to state with any certainty that such conflicts were between the 'valley' and 'hill' people, but we strongly suspect that this was the case, since difference is often turned into antagonism when things do go wrong and blame starts being cast. We see this in the modern world as well as in the past," Schulting added.