Different routes – an indicator of different cultures? Due to the fact that there were a number of different eastward routes for the spread of the barley population, the study suggests humans were choosing routes based on particular attributes of acting according to environmental adaptation. Choice and environment, therefore, are crucial factors for the spread of staple foods in prehistory. These different routes include ones to the north and south of the Iranian Plateau; through the Inner Asian Mountain Corridor in Central Asia, possibly connecting up to the Chinese section of the Silk Road; a high altitude spread on the southern edge of the Tibetan Plateau; a high latitude spread through the northern steppe; two distinct spreads into Japan; and a maritime route from South Asia. As previous research has provided radiocarbon dates, we know when the routes were followed. [caption id="attachment_8836" align="aligncenter" width="728"] Map showing proposed routes of spread of six different ancestral populations of barley landraces. Direct radiocarbon dates from archaeological barley grain have enabled the timing of these different routes to be elucidated. Credit: D. Lister[/caption]
Impacting rice-growing in East AsiaLead author Dr Diane Lister, a researcher at the McDonald Institute for Archological Research at the University of Cambridge, says: “One barley population is widespread, particularly around the coastlines. This population may have travelled eastwards via a maritime route from South Asia, via Southeast Asia. This particular population is made up of winter-sown varieties of barley, which are thought to be important in rice-growing areas of East Asia, where a crop of rice is commonly grown in the summer months, and barley adapted to winter-sowing regimes can be planted after the rice harvest. The development of multi-cropping practices during prehistory is thought to have greatly increased productivity and stability, enabling more complex societies to develop.” [caption id="attachment_8837" align="aligncenter" width="257"] Diane Lister at work in the Glyn Daniel laboratory for archaeogenetics at the McDonald Institute for Archaeological Research, University of Cambridge Credit: A. Clarke[/caption]
Moulding Tibetan culture“Another barley population predominates on the high Tibetan Plateau. This barley has a naked grain, making it a particularly attractive staple, as it doesn’t require the pearling process that hulled barley requires for human consumption. Along with the herding of yak, this naked type of barley is an essential for the Tibetan way of life, and their importance are clearly seen in the offerings of naked barley grains and yak butter in Tibetan Buddhist temples around the region. The staple carbohydrate eaten by the Tibetans is tsampa, made from roasted naked barley flour and mixed with salty Tibetan butter tea.” [caption id="attachment_8835" align="aligncenter" width="590"] Ethnically Tibetan women winnowing naked barley on a road on the edge of the Tibetan Plateau, near Xiahe, Gansu Province, China.
Photo credits Diane Lister[/caption]