Nomadic sheepherders dispersed domesticated grains in the earliest known East-West exchange 5,000 years ago—more than 2,000 years earlier than previously thought.
Charred grains of barley, millet, and wheat deposited nearly 5,000 years ago at campsites in the high plains of Kazakhstan show that nomadic sheepherders played a surprisingly important role in the early spread of domesticated crops throughout a mountainous east-west corridor along the historic Silk Road.
“Our findings indicate that ancient nomadic pastoralists were key players in an east-west network that linked innovations and commodities between present-day China and southwest Asia,” says study coauthor Michael Frachetti, an associate professor of archaeology at Washington University in St. Louis and principal investigator on the research project.
“Ancient wheat and broomcorn millet, recovered in nomadic campsites in Kazakhstan, show that prehistoric herders in Central Eurasia had incorporated both regional crops into their economy and rituals nearly 5,000 years ago, pushing back the chronology of interaction along the territory of the ‘Silk Road’ more than 2,000 years,” Frachetti says.
The study, published in the Proceedings of the Royal Society B, establishes that several strains of ancient grains and peas had made their way across Eurasia thousands of years earlier than previously documented.
While these crops have been known to exist much earlier in ancient China and Southwest Asia, finding them intermingled in the Bronze Age burials and households of nomadic pastoralists provides some of the earliest concrete signs for east-west interaction in the vast expanse of Eurasian mountains and the first botanical evidence for farming among Bronze Age nomads.
Bread wheat, cultivated at least 6,000 years ago in Southwest Asia, was absent in China before 2500 BC while broomcorn millet, domesticated 8,000 years ago in China, is missing in southwest Asia before 2000 BC.
Early economic systems
This study documents that ancient grains from eastern China and Southwest Asia had made their way to Kazakhstan in the center of the continent by 2700-2500 BC (nearly 5,000 years ago).
“This study starts to rewrite the model for economic change across Eurasia,” says first author Robert Spengler, a paleoethnobotanist and research associate. “It illustrates that nomads had diverse economic systems and were important for reshaping economic spheres more generally.”
“This is one of the first systematic applications of archaeobotany in the region, making the potential for further future discovery very exciting,” Spengler says.
‘Agents of change’
“Finding this diverse crop assemblage at Tasbas and Begash illustrates first evidence for the westward spread of East Asian and Southwest Asian crops eastward, and the surprise is that it is nomads who are the agents of change,” Frachetti says.
Doumani led the excavations at Tasbas in Kazakhstan while Rouse co-led the excavations at Ojakly in Turkmenistan. Coauthors contributed from the Washington University in St. Louis; Universita`degli Studi di Bologna, Italy; and the Institute of Archaeology in Kazakhstan.
The National Science Foundation, Lambda Alpha National Honor Society, the Mary Morris-Stein Foundation, Wenner-Gren, George F. Dales Foundation, and International Research & Exchanges Board IARO supported the study.