Millet: The first Chinese takeaway?

In a paper published this week (Friday, May 8th), archaeologists from the University of Cambridge reveal that the cultivation of broomcorn millet may have spread to the West after beginning on early Chinese farms.

The transition from gathering food in the wild to producing it on farms was the greatest revolution in human ecological history. Until relatively recently, prehistorians believed that it began in the Fertile Crescent of the Near East, between 12,000 and 7,000 years ago. Early communities there began to produce the so-called “founder crops” such as wheat and barley.

More recently, it has become clear that early Chinese communities domesticated their own grains, such as rice and millet, independently of any western influence. Until now, however, no evidence has emerged of such methods spreading from China to the West.

Writing in the journal Science, Professor Martin Jones and research colleague Xinyi Liu draw together evidence from a number of recent excavations (including their own) to suggest that millet may have made precisely that journey.

Charred remnants of millet grains found in Neolithic farmsteads in northern China show that the crop was being cultivated there as long as 8,000 years ago. Within the following millennium, it started to appear in Europe. In this period, millet grains have been identified from more than 20 sites west of the Black Sea.

The spread is much wider than that of the other major Chinese crop of the period – rice – and suggests that millet farming was pioneered in China and then began to catch on, moving slowly westwards. More importantly, the shift pre-dates the eastward spread of wheat and barley from the Fertile Crescent by at least 2,000 years.

“As recently as the late 1990s, many people still viewed Chinese agriculture as an import from the West,” Professor Jones said. “That picture is starting to change as it becomes possible to study the dynamics of Chinese agriculture itself. It now seems to be the case that there were early farms whose ideas progressed far beyond China.

“It is certainly the case that this Chinese crop got to Europe long before any of the Fertile Crescent crops reached China. It didn’t kick-start European agriculture, but it arrived here very early. In that sense it is a hint that the idea of cultivation was one that travelled both ways.”

Millet may have been even more important than rice in the diet of the Neolithic communities of northern China. Archaeological finds suggest that it was used to make noodles and, perhaps at a later stage, wine. In the 13th century Marco Polo recorded that the Chinese prepared it as a gruel cooked in milk.

The small millet seed is often found as a charred remnant in the pits and hearths uncovered on the sites of Neolithic Chinese farms. By comparing these finds, archaeologists have observed that over time, the grains gradually become bigger. The change in size is believed to be a sign that the plant was being grown selectively for the biggest and best crop, rather than gathered in the wild.

The paper also suggests that the revolutionary transition from hunter-gathering to farming in China may have taken place so slowly that it was almost imperceptible to people at the time.

By examining the stem and chaff that surrounded rice grains, archaeologists can determine whether the rice was wild or domesticated. In wild rice, the grain head breaks up as soon as the grain is formed, but in domesticated rice, it remains attached to the stem and it is the farmer who pulls the two apart. The shape of the “spikelet”, which attaches grain to stem, often reveals whether they detached naturally (as with wild rice) or were pulled apart.

These physical differences have enabled archaeologists to determined the genetic changes that rice underwent as it became domesticated. The examination of archaeological rice chaff recovered from the Lower Yangtze River region southern China has shown that the change was extremely slow. The proportions of harvested plants with or without these signs of domestication changed by just a few percent in each human lifetime.

The paper suggests that this was probably because people were not simply setting down their hunting spears and turning to farming – rather, they continued to gather wild foods such as fruits, nuts and acorns even as they started to farm rice. The result was that the rice continued to interbreed with wild crops.

While the first signs of domestication in rice crops appear on sites dating back to between 12,000 and 10,000 years ago, therefore, domesticated rice does not appear to the exclusion of its wild cousin until 5,000 years ago.

The overall picture, the paper suggests, is one in which “the domestication of plants has been a continuing process, made up of episodes of both rapid and gradual change.” As that occurred, the exchange of ideas and methods that lead to the agricultural revolution of prehistory may, on the evidence of millet finds, have been taking place in both directions.

“There is still a misconception that the ‘civilising’ effect of farming was purely a Western invention,” Professor Jones added. “Gradually, this sort of evidence is helping to overturn that mistaken belief.”