Barley may have been essential to the human conquest of Tibet, according to new research.
Artifacts including bones and teeth of animals, along with traces of crops, dating from 3,600 years ago, were found in Tibet, suggesting permanent settlements had spread to these altitudes by that time. A total of 53 archaeological sites were explored, at altitudes ranging from 8,200 to 11,150 feet above sea level. These historic areas were spread across 800 miles.
Human inhabitants spent short periods of time in Tibet starting 20,000 years ago, during the last major ice age. The earliest semi-permanent structures discovered, so far, in the region date to 5,200 in the past. However, these new findings, including evidence of prevalent crops and livestock, reveal more intricate designs than needed just to hunt game.
"[O]ur findings show that not only did these farmer-herders conquer unheard of heights in terms of raising livestock and growing crops like barley and millet, but that human expansion into the higher, colder altitudes took place as the continental temperatures were becoming colder," Martin Jones of the department of archeology at Cambridge University said.
Living conditions at such great altitudes would have presented significant challenges to early residents of the mountainous climate. How these people overcame difficulties and learned to survive in Tibet has been difficult to ascertain, as first-hand evidence from that time is rarely discovered.
Jones advocates genetic studies of humans in the region, along with crops grown in the area. This investigation could include examination of genetic changes in humans and plants that allowed them to thrive in the thin air of the mountainous region. This investigation could assist researchers studying the development of the human civilization in Tibet and beyond.
Barley and wheat - western crops grown in the Fertile Crescent were brought to Tibet by human migrants to the mountains. There, the plants became an invasive species, displacing the native foxtail millet and broomcorn, which do not provide the nutrition needed to live at great altitude.
Grains including barley and wheat were discovered at each of the 53 archaeological sites examined, while remains of livestock, including bones and teeth, were recovered from 10 locations. Examination of the settlements revealed that between 5,200 and 3,600 years ago, humans populated regions in Tibet at altitudes nearly two miles above sea level.
"The more we learn about rich ecology of past and present societies around Tibetan Plateau, and the wider range of plants and animals they raised in the world's more challenging environments, the more options we will have for thinking through challenging issues in the present and in the future," Xinyi Liu of Washington University said.
Study of the role barley may have played in allowing for permanent human settlements in Tibet was profiled in the journal Science.