Wheat and barley were exotic grains that were “incompatible” with local...

A new study in PLUS ONE Under the direction of Xinyi Liu, Associate Professor of Archeology in Arts & Sciences, it focuses on the ancient history of basic grain across China, a country known for its diverse food products and the early introduction of many domesticated plants.

The authors used data from the bones of nearly 2,500 people to map patterns of changing kitchens over 6,000 years. They argue that the regional differences in food traditions they have uncovered are not based on a traditional narrative of “stages” of modes of subsistence – that is, hunting first, then foraging, then pastoralism and finally farming – but rather on choices that have been combined and discarded modes of subsistence in a number of innovative ways over millennia.

“In ancient China, subsistence diversity and regional differences coexisted for thousands of years,” said Liu. “It primarily reflected people’s choice – not their evolutionary status.”

A second conclusion from the study concerns cooking. The authors suggest that culinary tradition is one of the main reasons why novel grains like wheat and barley were only gradually accepted by people in central China – especially in the region near the Loess Plateau – after they were introduced from southwest Asia about 4,000 years ago. But the same new plants were quickly adopted in western China.

“The timing of the relocation of novel food crops in prehistoric times reflects a number of decisions that different communities had to make,” said Liu. “These decisions were sometimes driven by environmental pressures and sometimes by social conditions or culinary conservatism.

“After 2,000 BC Wheat and barley were probably grown in the fields in central China. But they didn’t have staple status either in the kitchen or on the dining tables. Why they were originally neglected cannot be explained by ecological or social factors alone. We think the way grain was cooked played a role. ”

Millet in the north – and nuts, tubers, fruits and rice in the south

Cereal grains – including wheat, rice, barley, and millet – are the most important food sources in the world today. However, understanding how these foods were created and distributed around the world requires a global effort.

Liu worked with Rachel EB Reid of the Virginia Polytechnic Institute (formerly WashU) for this new analysis. They compiled published data of stable carbon and nitrogen isotopic compositions measured from 2,448 human skeletal samples from 128 archaeological sites across China. The isotope data from more than 90 previous studies can be read as indicators of what types of food these people predominantly ate, allowing scientists to identify conspicuous patterns at the continental level.

“By compiling an extensive set of published carbon and nitrogen isotope data from across China, we had a wonderful opportunity to study trends in time and space,” said Reid. “We were not only able to show that the selection of staple foods is deeply rooted and geographically differentiated, but also that culinary traditions could have influenced the reception of new plants.”

They found that Chinese staple cuisine was established before 2000 BC. Great distinction between northern and southern cultures, while younger cultures were dominated by east-west differences.

“Early on, we saw a contrast between the northern and southern cuisines that began about 8,000 years ago,” said Liu.

People in the north ate millet while those in the south ate a variety of nuts, tubers, fruits, and rice. The bone records show how the differences in the kitchen became even more apparent over time.

“One of the most important findings is that the tradition of consuming millet as a staple food is very old and originated around 8,000 years ago,” said Liu. “In Xinglonggou, an early Neolithic area in southern Inner Mongolia, we estimated the proportional contribution of millet to human nutrition at more than 50%. Soon after it was domesticated, or perhaps during the domestication process, millet had become a staple grain. ”

The distinction between north and south in ancient China is reflected in the geographic structure of another early agricultural center, the Southwest Asian “Fertile Crescent”, where human livelihoods differed significantly between the northern “hill flanks” and the southern Mesopotamian alluvium.

“In both East and West Asia, the early peoples seem to have combined modes of subsistence in a number of innovative hybrids – and shifted to other hybrids fairly easily as they chose,” Liu said. “The subsistence strategies could be the result of already existing social and political conditions, not the other way around, as previously assumed.”

Difference driven by culinary practice

The early north-south divide in staple foods was due to environmental differences that favored certain plant resources under different conditions, such as those that performed better in wetlands or arid regions. However, the east-west divide was due to differences in culinary practice, as the eastern cooking habits of boiling and steaming were less suited to the introduction of new grains like wheat and barley, believe Liu and Reid.

They cite influential work by two London-based scholars, Dorian Fuller and Mike Rowlands, who show that early communities were marked by a difference in food preparation techniques: culinary traditions based on the cooking and steaming of grains in East Asia as well as on the Milling grain and baking the flour are based in western Asia.

“These culinary differences between East and West are deeply rooted and probably older than the agricultural origins,” said Liu. “Current archaeological evidence suggests that these various cooking technologies were rooted well before the domestication of plants in the Pleistocene.”

Liu said, “The question is, what happens when grains like wheat and barley, rooted in the tradition of grinding and baking bread-making, step into a different kitchen – one that prefers cooking and steaming and eating with whole grains -? ”

Liu and colleagues have previously shown that the introduction of wheat to China may include choices based on phenotypic traits that are better adapted to the Eastern cooking and steaming tradition.

The isotopic data analyzed in this new study show a very gradual introduction of wheat and barley as staple foods in central China as opposed to rapid uptake in western China. The authors relate this to their intolerance to local whole grain meals that rely on cooking and steaming.

“We can always relate this prehistoric life to our own experience of eating and cooking,” said Liu. “If nothing else, it takes a lot longer to cook whole grains on a cooking set, and it tastes very different from cooked rice or millet.”