9,000 years ago, a community with modern urban problems

Some 9,000 years ago, residents of one of the world's largest farming communities were also among the first humans to face the dangers of modern urban life.

Scientists studying the ancient ruins of Çatalhöyük in modern Turkey discovered that its inhabitants – 3,500 to 8,000 inhabitants at its peak – were overcrowded, suffering from infectious diseases, violence and environmental problems.

In an article published on June 17, 2019 in the Proceedings of the National Academy of Sciences, an international team of bioarchaeologists report new discoveries based on 25 years of study of human remains found at Çatalhöyük.

The findings give an idea of ​​what man looked like from a nomadic lifestyle to a more sedentary life built around agriculture, said Clark Spencer Larsen, lead author of the Study and professor of anthropology at Ohio State University. .

"Çatalhöyük was one of the first proto-urban communities in the world and residents experienced what was happening when we brought together many people in a small area for an extended period," Larsen said.

"This paved the way for the current situation and the challenges we face in urban areas."

Çatalhöyük, in what is now south-central Turkey, was inhabited between 7100 and 5950 BC. Excavated for the first time in 1958, the site extends over 13 hectares and includes nearly 21 meters of deposits covering a period of continuous occupation of 1,150 years.

Larsen, who started his work on the site in 2004, was one of the leaders of the human remains team as part of the larger Çatalhöyük research project, led by Ian Hodder of the University of Stanford. A co-author of the PNAS The paper, Christopher Knüsel from the University of Bordeaux in France, was co-head of the bioarchaeology team with Larsen.

The field work in Çatalhöyük ended in 2017 and the PNAS The paper represents the culmination of bioarchaeology work on the site, said Larsen.

Çatalhöyük began as a small colony around 7100 BC. BC, probably made up of some mud brick houses in what the researchers call the Early period. It reached its peak between 6700 and 6500 BC. BC before the rapid decline of the population at the end of the period. Çatalhöyük was abandoned around 5950 BC.

Agriculture has always been an important part of life in the community. The researchers analyzed a chemical signature in the bones, called stable carbon isotope ratios, to determine that residents had a diet rich in wheat, barley and rye, as well as a range of plants not domesticated.

Stable nitrogen isotope ratios have been used to document the presence of protein in their diet, derived from sheep, goats and non-domestic animals. Domestic cattle were introduced at the end of the period, but sheep have always been the most important domestic animals in their diet.

"They grew and raised animals as soon as they created the community, but they intensified their efforts as the population grew," Larsen said.

The grain-rich diet meant that some residents were soon developing tooth decay, one of the "diseases of civilization," Larsen said. The results showed that about 10 to 13% of the adult teeth found at the site showed signs of dental caries.

Changes over time in the shape of the cross sections of the leg bones showed that community members at the end of the Çatalhöyük period were walking much more than the original inhabitants. This suggests that residents have had to move agriculture and grazing further away from the community over time, said Larsen.

"We believe that environmental degradation and climate change have forced community members to move away from the settlement to settle on farms and find supplies such as firewood. heating, "he said. "This contributed to the ultimate disappearance of Çatalhöyük."

Other research suggests that the climate in the Middle East has become drier during the history of Çatalhöyük, which has made agriculture more difficult.

The results of the new study suggest that residents have suffered from a high infection rate, probably due to overcrowding and poor hygiene. Up to one third of the remnants of the early period show signs of bone infections.

At the height of the population, the houses were built like apartments with no space in relation to each other. Residents entered and exited ladders on the roofs of houses.

Excavations have shown that interior walls and floors are often covered with clay. And while residents kept their floors virtually free of debris, the analysis of walls and floors of homes showed traces of animal and human faeces.

"They live in overcrowded conditions, with garbage pits and animal pens right next to some of their houses, so there is a whole series of sanitation problems that could contribute to the spread of disease. infectious, "said Larsen.

The overcrowded conditions in Çatalhöyük may also have contributed to high levels of inter-resident violence, according to the researchers.

In a sample of 93 skulls from Çatalhöyük, more than a quarter, or 25 people, showed signs of healed fractures. And 12 of them were victims more than once, with two to five injuries over a period of time. The shape of the lesions suggests that blows to the head from hard, round objects caused them – and that clay balls of the right size and shape were also found at the site.

More than half of the victims were women (13 women and 10 men). And most of the injuries were at the top or back of the head, suggesting that the victims were not facing their attackers when they were hit.

"We saw an increase in cranial lesions during the middle period, when the population was the largest and the most dense," said Larsen.

"One could argue that overcrowding leads to increased stress and conflict within the community."

Most people have been buried in pits dug into the soil of homes and researchers believe that they were buried under the houses in which they lived. This led to an unexpected discovery: most members of a household were not biologically related.

The researchers discovered this by discovering that the teeth of individuals buried under the same house were not as similar as one would expect if they were related.

"The morphology of the teeth is highly genetically controlled," said Larsen. "Relatives have similar variations in the crown of their teeth and we have not found that in people buried in the same houses."

Further research is needed to determine the relationships of the people who lived together in Çatalhöyük, he said. "It's still kind of a mystery."

Overall, Larsen said that Çatalhöyük's importance is that it was one of the first neolithic "mega-sites" in the world built around agriculture.

"We can learn more about the immediate origins of our lives today, our organization in communities, and many of the challenges we face today are the same as the ones they have had. at Çatalhöyük – they have been amplified. "