Xinyi Liu

Agriculture facilitated permanent human occupation of the Tibetan Plateau after 3600 B.P.

Colonizing the roof of the world Humans only settled permanently on the Tibetan plateau about 3600 years ago. Chen et al. examined archaeological crop remains unearthed in northeastern Tibet, which elucidate the timing of agricultural settlement. Although much earlier traces of humans in Tibet have been dated to 20,000 years ago, year-round presence at the highest altitudes appears to have been impossible until the advent of suitable crops, such as barley. Surprisingly, these prehistoric farming communities expanded onto the plateau at the same time as climate was cooling. Science, this issue p. 248 Archaeobotanical data sets from the Tibetan Plateau reveal the Holocene prehistory of high-altitude human settlement. Our understanding of when and how humans adapted to living on the Tibetan Plateau at altitudes above 2000 to 3000 meters has been constrained by a paucity of archaeological data. Here we report data sets from the northeastern Tibetan Plateau indicating that the first villages were established only by 5200 calendar years before the present (cal yr B.P.). Using these data, we tested the hypothesis that a novel agropastoral economy facilitated year-round living at higher altitudes since 3600 cal yr B.P. This successful subsistence strategy facilitated the adaptation of farmers-herders to the challenges of global temperature decline during the late Holocene.

Millets across Eurasia: chronology and context of early records of the genera Panicum and Setaria from archaeological sites in the Old World.

We have collated and reviewed published records of the genera Panicum and Setaria (Poaceae), including the domesticated millets Panicum miliaceum L. (broomcorn millet) and Setaria italica (L.) P. Beauv. (foxtail millet) in pre-5000 cal b.c. sites across the Old World. Details of these sites, which span China, central-eastern Europe including the Caucasus, Iran, Syria and Egypt, are presented with associated calibrated radiocarbon dates. Forty-one sites have records of Panicum (P. miliaceum, P. cf. miliaceum, Panicum sp., Panicum type, P. capillare (?) and P. turgidum) and 33 of Setaria (S. italica, S. viridis, S. viridis/verticillata, Setaria sp., Setaria type). We identify problems of taphonomy, identification criteria and reporting, and inference of domesticated/wild and crop/weed status of finds. Both broomcorn and foxtail millet occur in northern China prior to 5000 cal b.c.; P. miliaceum occurs contemporaneously in Europe, but its significance is unclear. Further work is needed to resolve the above issues before the status of these taxa in this period can be fully evaluated.

River valleys and foothills: changing archaeological perceptions of North China's earliest farms

Early farming in northern China featured the cultivation of two species of millet, broomcorn and foxtail. Although previously seen as focused on the Yellow River, the authors show that the earliest agriculture is actually found in the foothills of the neighbouring mountain chains, where drier and better drained locations suited millet cultivation, particularly broomcorn. In this they echo new thoughts on the locale of early agriculture in south-west Asia, on the hilly flanks of the Fertile Crescent rather than in the valleys of the Nile or the Euphrates.

Food globalization in prehistory

Abstract Plant sources of starch have been domesticated in several parts of the world. By the second millennium bc in various parts of Eurasia, such starchy crops are encountered, not only around their geographical regions of origin, but also at considerable distances from them. Drawing on evidence from across Eurasia, this paper explores this episode of food globalization in prehistory, comparable in the scale of its impact on global diets to the Columbian Exchange of historic times. Possible reasons for the earlier episode of food globalization are discussed and situated within a broader consideration of cross-continental contact in prehistory.

The early chronology of broomcorn millet ( Panicum miliaceum ) in Europe

The majority of the early crops grown in Europe had their origins in south-west Asia, and were part of a package of domestic plants and animals that were introduced by the first farmers. Broomcorn millet, however, offers a very different narrative, being domesticated first in China, but present in Eastern Europe apparently as early as the sixth millennium BC. Might this be evidence of long-distance contact between east and west, long before there is any other evidence for such connections? Or is the existing chronology faulty in some way? To resolve that question, 10 grains of broomcorn millet were directly dated by AMS, taking advantage of the increasing ability to date smaller and smaller samples. These showed that the millet grains were significantly younger than the contexts in which they had been found, and that the hypothesis of an early transmission of the crop from east to west could not be sustained. The importance of direct dating of crop remains such as these is underlined.

Origins of agriculture in East Asia.

During the initial phase of cereal cultivation in East Asia, domesticated traits emerged only slowly. Some of the worlds most important crops, including rice and soybean, originate from eastern Asia. This region is also the original home of several minor crops, such as buckwheat and certain types of millet. In their search for the earliest farms, archaeologists have been drawn to Chinas two major river valleys: the Yellow River in the north and the Yangtze River in the south. Grains of broomcorn and foxtail millet have been found in Neolithic farmsteads in the Yellow River region (1, 2), and sites in the Yangtze River region have yielded the worlds earliest evidence of harvested rice grains (3).

The earliest evidence of millet as a staple crop: New light on neolithic foodways in North China

There is a growing body of archaeobotanical evidence for the harvesting of millet in Eurasia prior to 5,000 cal. BC. Yet direct evidence for the extent of millet consumption in this time period is rare. This contradiction may be due to millet crops making only a minor contribution to the diet before 5,000 BC. In this article, drawing from recent excavations in North China, we present evidence for millet crops making a substantial contribution to human and animal diets in periods, which correspond chronologically with the time depth of the archaeobotanical record. We infer that in eastern Inner Mongolia, human adoption of millets, which may or may be not related to substantial agriculture, happened at the Early Neolithic, with direct dates between 5,800 and 5,300 cal. BC.

Why move starchy cereals? A review of the isotopic evidence for prehistoric millet consumption across Eurasia

The spread of agriculture is an important topic of archaeological research, but relatively few studies address the drivers behind the spread of specific species empirically. Here we use published isotopic data to consider whether the millets spread from their putative domestication centre in the East to western Eurasia for use as a staple food. We show that the consumption of significant quantities of millet was both far more sporadic than the earliest appearance of millet might suggest and delayed. This is not to say that millet was not consumed, rather that any consumption was below the level of isotopic detectability, and thus millet cannot generally be considered a staple. Nevertheless, individuals who regularly consumed millet occur both as typical members of their population and as unusual individuals. The reasons for this pattern open up new questions about, and avenues of research into, the spread of agriculture.

From necessity to choice: dietary revolutions in west China in the second millennium BC

Abstract This article explores the context of the long-distance translocation of crops in prehistory. We draw upon contrasts in the isotopic signatures of Southwest Asian crops, including wheat and barley – C3 plants, compared to Asian millets – C4 plants, to investigate a key region of trans-Eurasian exchange, the Chinese province of Gansu. The isotopic results demonstrate that in Gansu province prior to 2000 cal. bc, the staples were millets. Between 2000 and 1800 cal. bc, there was a significant shift in staple foods towards the Southwest Asian crops. In the broader regional context, however, it would seem that these novel crops were not consumed in large quantities in many parts of China during the second millennium bc. This suggests that, while the Southwest Asian crops were adopted and became a staple food source in Gansu province in the second millennium bc, they were disregarded as staple foods elsewhere in the same millennium.

Journey to the east: Diverse routes and variable flowering times for wheat and barley en route to prehistoric China

Today, farmers in many regions of eastern Asia sow their barley grains in the spring and harvest them in the autumn of the same year (spring barley). However, when it was first domesticated in southwest Asia, barley was grown between the autumn and subsequent spring (winter barley), to complete their life cycles before the summer drought. The question of when the eastern barley shifted from the original winter habit to flexible growing schedules is of significance in terms of understanding its spread. This article investigates when barley cultivation dispersed from southwest Asia to regions of eastern Asia and how the eastern spring barley evolved in this context. We report 70 new radiocarbon measurements obtained directly from barley grains recovered from archaeological sites in eastern Eurasia. Our results indicate that the eastern dispersals of wheat and barley were distinct in both space and time. We infer that barley had been cultivated in a range of markedly contrasting environments by the second millennium BC. In this context, we consider the distribution of known haplotypes of a flowering-time gene in barley, Ppd-H1, and infer that the distributions of those haplotypes may reflect the early dispersal of barley. These patterns of dispersal resonate with the second and first millennia BC textual records documenting sowing and harvesting times for barley in central/eastern China.