Intensification in pastoralist cereal use coincides with the expansion of trans-regional networks in the Eurasian Steppe

The pace of transmission of domesticated cereals, including millet from China as well as wheat and barley from southwest Asia, throughout the vast pastoralist landscapes of the Eurasian Steppe (ES) is unclear. The rich monumental record of the ES preserves abundant human remains that provide a temporally deep and spatially broad record of pastoralist dietary intake. Calibration of human δ13C and δ15N values against isotope ratios derived from co-occurring livestock distinguish pastoralist consumption of millet from the products of livestock and, in some regions, identify a considerable reliance by pastoralists on C3 crops. We suggest that the adoption of millet was initially sporadic and consumed at low intensities during the Bronze Age, with the low-level consumption of millet possibly taking place in the Minusinsk Basin perhaps as early as the late third millennium cal BC. Starting in the mid-second millennium cal BC, millet consumption intensified dramatically throughout the ES with the exception of both the Mongolian steppe where millet uptake was strongly delayed until the end of first millennium cal BC and the Trans-Urals where instead barley or wheat gained dietary prominence. The emergence of complex, trans-regional political networks likely facilitated the rapid transfer of cultivars across the steppe during the transition to the Iron Age.- Signifcant Diferences in Linear Regression Slopes Between Humans and Livestock Indicate Pastoralist Cereal Consumption - Regional Variation in the Intensifcation in Cereal Consumption -- Southwestern Siberia. -- Minusinsk Basin -- Southeastern Kazakhstan. -- Central Kazakhstan. -- Mongolia. -- Trans-Urals. -- The Northern Caucasus -- Temporal disparity between frst evidence of cereals, subsequent incorporation into pastoralist diets, and intensifcation of cereal consumption in the ES. -- Participation in trans-regional political exchange networks redirected pastoralist dietary intake - Discussion - Method