A Stone Age tribe in Central Europe maintained its hunter-gatherer way of life for 2,000 years after the arrival of farming, surprising anthropologists.

The tribe in Central Europe ate almost exclusively freshwater fish until around 3000 B.C., University of British Columbia researchers discovered by doing a chemical analysis of bones found in a German cave.

“I have never seen anything like that,” said Olaf Nehlich, a post-doctoral researcher in UBC’s department of anthropology who co-authored a paper describing the results. It was published this week in Science Express.

He and his colleagues were surprised because when agriculture was introduced to Europe around 5000 B.C., the development quickly led to the disappearance of the hunter-gathering lifestyle in the rest of the continent, Nehlich said.

In fact, anthropologists had previously thought that there were no hunter gatherers left in Central Europe not long after after 5000 B.C.

But when Nehlich and UBC anthropology professor Michael Richards analyzed protein in bones and teeth of 29 people found at the Blätterhöhle archeological site in Hagen, Germany, they found that some ate only wild, foraged food, even though carbon-14 dating showed that they lived as much as 2,000 years after the arrival of farming in the region.

In all that time, the hunter-gatherers lived alongside and buried their dead in the same cave as another group of people who ate nothing but agricultural crops and domestic animals such as sheep and cattle. The remains of those farmers were also found in the cave.

No interbreeding

Despite the fact that they were neighbours, there was little, if any, interbreeding between the two cultural groups, according to the results of a DNA analysis by Ruth Bollongino, lead author of the paper, and her colleagues at Johannes Gutenberg University of Mainz.

Nehlich acknowledged that lack of interbreeding may have been due to cultural reasons, but said that is pure speculation in the absence of evidence.

He said it’s not clear why the hunter-gatherers of Blätterhöhle managed to maintain their lifestyle for so long after it had died out in other parts of Europe.

Typically, he said, the arrival of farming led to widespread deforestation and the disappearance of wildlife that allowed hunters to sustain themselves. In the case of the Blätterhöhle site, the analysis showed that hunter gatherers who used the cave before the arrival of agriculture ate a land-based diet of wild game.

But the hunter-gatherers who lived at the same time as the farmers ate almost only fish — a change in subsistence strategy that might have allowed them to maintain their lifestyle much longer, given the abundance of large rivers in the area, Nehlich said.

Nehlich became involved in the study while he was a researcher at the Max Planck Institute in Leipzig, Germany. At that time, the excavation of the bones was underway, and Bollongino and her colleagues were hoping to get some information about the diets of the people who had been buried at the Blatterhohle site.

Once, the excavation was complete, Nehlich moved to UBC to work with Richards, and brought some of the bones with him.

Richards’s lab has pioneered chemical techniques that allow scientists to get much more detail about the diets of humans and animals that lived long ago from an analysis of their bones. Carbon, nitrogen and sulphur, which enter the body through food and are incorporated into the proteins of the bones, have different isotopes — different varieties of the same element with slightly different masses. The ratio of the isotopes depends on the type of food they came from.

While other labs have been doing carbon and nitrogen isotope analysis for a while, Richards’s lab developed a new technique to measure the ratio of sulphur isotopes, Nehlich said. The new technique makes it possible to tell whether an individual ate mainly land-based game, a diet based on freshwater fish and shellfish, or a diet based on marine fish and shellfish.

The study was funded by the German Research Foundation, the European Commission’s Marie Curie Initial Training Network, the Max Planck Society, the Social Sciences and Humanities Research Council of Canada, the Synthesis Project of the European Union Seventh Framework program and the University of Mainz.