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What did people eat in the Stone Age before the advent of farming around 10,000 years ago? A long-held stereotype – one that has influenced modern diets – is that ancient people hunted large animals and feasted on a huge steak.
But new research into a Paleolithic group known as the Iberomaurusians, hunter-gatherers who buried their dead in what is now Taforalt Cave in Morocco between 13,000 and 15,000 years ago, is adding to a growing body of evidence that challenges the notion that human ancestors depended mainly on meat. , according to a study published Monday in the journal Nature Ecology & Evolution.
The scientists analyzed chemical signatures preserved in bones and teeth belonging to at least seven different Iberomaurus and found that plants, rather than meat, were their main source of dietary protein.
“Our analysis showed that these hunter-gatherer groups included an important amount of plant material, wild plants in their diet, which changed our understanding of the diet of pre-agricultural populations,” said the study’s lead author Zineb Moubtahij, son doctoral student. at Géosciences Environnement Toulouse, a research institute in France, and the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.
The share of plant resources as a source of dietary protein in humans whose remains have been studied was similar to that seen by early farmers from the Levant, the present-day Eastern Mediterranean countries, where the consumption of plants has been documented. and on plant farming for the first time.
Researchers also saw a higher number of tooth cavities among the Taforalt specimens than is typically seen with hunter-gatherer remains of that period. The evidence indicated that the Iberomaurusians ate “starchy fermentable plants” such as wild grains or acorns, according to the study. The findings raise some interesting questions about how agriculture spread across different regions and populations.
“Although not everyone got their proteins mainly from plants at Taforalt, it is unusual to document such a high number of plants in the diet of a pre-agricultural population,” co-author Klervia Jaouen, a researcher at Géosciences Environnement Toulouse, said in a statement. email.
“This is probably the first time that a significant plant-based component in a Paleolithic diet has been documented using isotope techniques,” said Jaouen.
Demystifying ancient diets
The researchers used a technique called stable isotope analysis to learn about the diet of each of the Iberomaurusians studied.
Nitrogen and zinc isotopes (elemental variations) in college and tooth enamel can reveal the extent to which ancient diets once included meat, while carbon isotopes can shed light on whether meat or fish was the main source of protein. .
“People eat these foods and the isotope information is recorded in tissues like bones and teeth,” Moubtahij said. “By analyzing these tissues that we find in archaeological records, we will know if a person ate more meat or if they ate more plant-based food.”
The isotope technique shows the amount of plant eaten but not the type. However, the botanical remains of charred sweet acorns, pistachios, pine nuts, wild oats and pulses found at the site support the information obtained from the human remains. Grindstones found at the site also indicate that plant processing took place nearby.
However, the Iberomaurusians were not strict vegetarians, the study noted. Cut marks on the remains of Barbary sheep and gazelles, as well as ancient horse and cow mammals, indicated that some animals had been butchered and processed for food.
The increased reliance on plant food was likely driven by a number of factors – including a wider range of edible plants and possibly the depletion of large game species, according to the study.
Detached tips soon
The isotope analysis also found evidence of one case of early weaning, with starchy plant foods introduced into the infant’s diet before the child’s death at 6 to 12 months of age.
“This is in contrast to hunter-gatherer societies where extended periods of breastfeeding are the norm due to the limited availability of weaned foods,” according to the study.
The research only investigated the diets of one group of Stone Age hunter-gatherers. However, a similar study published in January – which analyzed the remains of 24 early humans from two burial sites in Peru from 9,000 to 6,500 years ago – showed that ancient diets in the Andes were made up of 80% plant material. and 20% meat. .
A November 2022 study revealed that Neanderthals and early Homo sapiens were sophisticated cooks, combining plant-based ingredients such as wild nuts, peas, peaches, lentils and wild mustard.
“I don’t think there is a normal diet for everyone (in this period), but it depends on the environment. People are resilient and flexible in their dietary habits,” said Moubtahij.
The work undermines the idea that the Stone Age diet was heavy on meat – a rigid assumption that underpins today’s dietary trends such as the Paleo diet. But the stereotype probably has its roots in past research, and there are a number of possible reasons.
Evidence of meat-eating, in the form of butchered animal bones, is often more “archeologically visible” than evidence of plant-eating, said Briana Pobiner, a research scientist and museum educator at the Human Origins Program in the Department of Anthropology at the Institute. Smithsonian National Museum of Natural History. She was not involved in the study.
Another reason for the idea that meat was central to early human diets is “the view that hunting was a key behavioral innovation early in our evolutionary history – rooted in part in early hunter-gatherer studies by scholars which mainly focused on males. men hunt big game and the important nutritional role of women gathering plant resources and smaller game has not been documented, discounted or minimized,” she said via email.
Agricultural transition published
Jaouen said that in the Levant region, archaeologists have documented a similar plant-based diet among another group that practiced a hunter-gatherer lifestyle just before the development of agriculture, raising questions about why the transition did not occur. to farm at the same time among the group. the Iberomaurusian population.
“These results show that many populations at the end of the Paleolithic adopted a diet similar to that of farmers in terms of plant content,” she said.
The transition to agriculture was a complex process that happened at different times and proceeded at different rates, in different ways with different foods, in different places, Pobiner said.
“In other words, it was largely a local phenomenon that could involve transitional forms of maintenance – not just a global, sharp simultaneous transition,” she said.
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