New ancient DNA data on the origins and spread of sheep and cattle in northern China around 4000 BP

The time around 4000 BP marks a key stage from the Late Neolithic to the Early Bronze Age in China. During the time, sheep and cattle husbandry saw rapid development under the Qijia Culture in the Gansu-Qinghai region and also became more common in the Central Plains and Inner Mongolia. In this study, we performed ancient DNA analysis on sheep and cattle remains from four archaeological sites (Changning, Shimao, Taosi and Dashanqian) in northern China, and we obtained mtDNA D-loop fragments (overlapping 271 bp for sheep and overlapping 294 bp for cattle) from 22 of 26 sheep and 44 of 52 cattle remains. The mtDNA haplogroup data reveal that all the sheep DNA samples belong to sub-haplogroups A or B, and all the cattle DNA samples belong to haplogroup T3 or T4. The identification of these common haplogroups again confirms that the ancestors of these early sheep and cattle must have been introduced from outside China, likely from the Near East. The more detailed comparison of haplogroups also indicates potential intensified trade and cultural exchanges between different regions. Furthermore, this study also provides new ancient DNA data for better understanding the origins and spread of sheep and cattle in ancient China.