Periodic Reporting for period 4 - ASIAPAST (From herds to empire: Biomolecular and zooarchaeological investigations of mobile pastoralism in the ancient Eurasian steppe)
Reporting period: 2022-10-01 to 2024-03-31
WP2 results included isotopic data measured from human remains from Mongolia indicating herders consumed diets consisting primarily of terrestrial animal proteins. Bulk carbon isotope analyses of human remains also indicate that millet came into use extraordinarily late in Mongolia, coinciding with the rise of the Xiongnu empire. Strontium and oxygen isotopes analyses of ancient human teeth from Mongolia demonstrate regional circulation of Xiongnu intermediary elites that served to consolidate the power of the first ‘state on horseback’. Zooarchaeological analyses have revealed a shift in the importance of animals in ancient mortuary monuments in Mongolia, reflecting a shift in role of animals as a means of political negotiation. Stable isotope analyses of animal remains from Mongolia demonstrate wide variation in herd management strategies, including winter foddering and seasonal mobility. Stable isotope analyses of late prehistoric animal remains from Uzbekistan reveal strong influence of local environmental inputs in their isotopic composition, likely overriding the imprint of human animal management activities.
Main results from WP3 from organic residue analyses of pottery suggest that animal meats and fats had an outsized importance in the northern Kazakh steppe with little or no contribution from dairy, but dairy was an important food in the drier southern Kazakh steppe. Organic residue and biomarker analyses of pottery from Altai reveal complex food processing activities involving the use of unexpectedly diverse food resources throughout the Neolithic, Bronze, and Iron Ages. Proteomics analyses of dental calculus from Bronze and Iron Age human remains from Mongolia identify only uneven consumption of dairy across the Mongolian steppe despite previous work, based on a small sample size, asserting that dairy consumption was a key part of Bronze Age diets there. Initial proteomic analyses for dairy proteins (beta lactoglobulin) hint at marked temporal shifts in human dairy consumption in the Russian Altai and also Kazakhstan.
For WP4, ancient DNA analyses work on goats indicate that goats spread along two transmission pathways into the Eurasian steppe, the first along a northern route along the open steppe belt (northern Kazakhstan) and the second along the Inner Asian Mountain Corridor via the Tian Shian mountain range. WP4 results also include genetic evidence for the earliest domesticated sheep in the Altai at ca 3000 BC associated with the Afanasievo culture. Cytochrome b work confirms the persistence of sheep over goats in the Altai region.
ASIAPAST also ensured maximization of proteome recovered of beta lactoglobulin and alpha caseins in human dental calculus through development of a new paramagnetic bead approach that tests the influence of demineralization acid on recovered proteome complexity and sequence coverages matched for significant proteins. This work found that a protocol utilizing EDTA combined with paramagnetic beads increased proteome complexity, in some cases doubling the number of unique peptides and number of proteins matched, compared to protocols involving the use of HCl and either acetone precipitation or ultrafiltration. Altogether, this development increased sequence coverage of dietary milk proteins and has further implications for the study of diseases within these ancient populations by increasing the number of proteins of bacterial origin recovered from dental calculus.
Expected results until the end of the project include isolating establishing where and when hunter-gatherer and pastoralist mobility patterns changed and under what conditions, determine if there were regional distinctions in the demographic composition of livestock herds and the husbandry strategies used to manage them, document whether shifts in the intensity of processing of ruminant fat, milk fat, and fish oil correspond with changes in pastoralist dietary intake, and establish when and where the distinction between livestock as a primarily subsistence resource and livestock means to ideological and political expression emerged.