Early pastoral economies along the Ancient Silk Road: Biomolecular evidence from the Alay Valley, Kyrgyzstan

Abstract

The Silk Road was an important trade route that channeled trade goods, people, plants, animals, and ideas across the continental interior of Eurasia, fueling biotic exchange and key social developments across the Old World. Nestled between the Pamir and Alay ranges at a baseline elevation of nearly 3000m, Kyrgyzstan’s high Alay Valley forms a wide geographic corridor that comprised one of the primary channels of the ancient Silk Road. Recent archaeological survey reveals a millennia-long history of pastoral occupation of Alay from the early Bronze Age through the Medieval period, and a stratified Holocene sequence at the site of Chegirtke Cave. Faunal remains were recovered from test excavations as well as surface collection of material from recent marmot activity. Although recovered specimens were highly fragmented and mostly unidentifiable using traditional zooarchaeological methods, species identification via collagen mass fingerprinting (ZooMS) coupled with sex and first-generation hybrid identification through ancient DNA enabled preliminary characterization of the animal economy of Alay herders. Our new results indicate primary reliance on sheep at Chegirtke Cave (ca. 2200 BCE), with cattle and goat also present. The discovery of a large grinding stone at a spatially associated Bronze or Iron Age habitation structure suggests a mixed agropastoral economic strategy, rather than a unique reliance on domestic animals. Radiocarbon-dated faunal assemblages from habitation structures at nearby localities in the Alay Valley demonstrate the presence of domestic horse, as well as Bactrian camel during later periods. The current study reveals that agropastoral occupation of the high-mountain Alay corridor started millennia before the formal establishment of the Silk Road, and posits that ZooMS, when paired with radiocarbon dates and ancient DNA, is a powerful and cost-effective tool for investigating shifts in the use of animal domesticates in early pastoral economies.

Population Structure and Genetic Diversity of Sheep Breeds in the Kyrgyzstan

“…In the current study, the assumption of an influence of the Great Silk Road on the gene pool of local sheep seems to be plausible. Due to a specific geographical location and mountain landscape, the territory of modern Kyrgyzstan was the crossroad of the ancient civilizations and great empires involved in the world's famous exchange networks connecting China and South Asia with Central Asia and Europe (Williams, 2014;Spengler, 2015;Stevens et al, 2016;Taylor et al, 2018). Based on historical records, it is generally considered that the transcontinental trade channels had formed in the first millennium BCE (Christian, 2000).…”

“…The exchange and trade of livestock animals was one of the important elements of functioning of the West-East networks (Taylor et al, 2018). For example, horses raised in the Ferghana Valley were highly valued and were transported from Central Asia to China at the end of the first millennium BCE (Sinor, 1972;Taylor et al, 2018).…”

“…The exchange and trade of livestock animals was one of the important elements of functioning of the West-East networks (Taylor et al, 2018). For example, horses raised in the Ferghana Valley were highly valued and were transported from Central Asia to China at the end of the first millennium BCE (Sinor, 1972;Taylor et al, 2018). According to Spengler (Spengler, 2015), caravans along with goods brought sheep, goat, and cattle into the mountains by the late third millennium, while Stevens et al (Stevens et al, 2016) considered that sheep and taurine cattle reached China in 2000-1900BC (Stevens et al, 2016.…”

“…Furthermore, it is worth mentioning that the Kyrgyzstan, which is geographically located between Kazakhstan, Uzbekistan, Tajikistan, and China, played a crucial role as a gateway of the ancient Great Silk Road (Taylor et al, 2018). In fact, the trade channels through the Kyrgyz territory, including the iconic Irkeshtam Pass, remained unaltered during the whole existence of these links between the East and the West, while the other routes changed from time to time (Williams, 2014;Abdrisaev, 2017).…”

“…Along with trading of valuable goods (silk, spice, musk, tea etc. ), the vast exchange of domestic animals was inevitable (Boivin, 2017;Taylor et al, 2018). To date, large amounts of SNP genotyping data have been generated from worldwide popular sheep breeds (Kijas et al, 2012;Ciani et al, 2015) and local populations including Welsh (Beynon et al, 2015), Ethiopian (Edea et al, 2017), Chinese (Zhao et al, 2017), and Russian sheep (Deniskova et al, 2018).…”