Investigation of yak exploitation and identification of domestic buffalo bones by ZooMS
Yaks (Bos grunniens) have thrived on the hostile Qinghai-Tibetan Plateau (QTP) and adjacent highlands (Wiener, et al., 2003), and the domesticated yak is known as an “all-around” animal due to its contributions of milk, butter, meat, bone, fiber, labor, and especially dung for fuel and hides for making tent shelters. Since the yak has played an important role in enabling ancient people to conquer the QTP and for cultural development in the QTP, investigating the origin and spread of the domestic yak is very crucial to reconstruct human adaptations in this area.
It is difficult to identify yak bones if the skeleton is incomplete (Olsen, 1990). Consequently, only a few yak bones have been positively identified, making it difficult to study the origin and spread of the domestic yak from a zooarchaeological perspective (Flad, et al., 2007). Since milk could not be expected from wild animals, milk residue in pottery has been used to trace the origin and spread of bovine/ovine domestication (Evershed, et al., 2008), and gives solid evidence for early horse domestication (Outram, et al., 2009). Furthermore, proteomics could differentiate yak, cattle and goat milk (Yang, et al., 2013). Therefore, it is feasible to use proteomics and lipid analysis to identify yak milk residue in pottery.
Domestic water buffalo (Bubalus bubalis), derived from the wild buffalo (Bubalus arnee), is an integral component of traditional Asian rice cultivation agriculture. This water buffalo includes two subspecies: the river type (Bubalus bubalis bubalis) and the swamp type (Bubalus bubalis carabensis). The water buffalo found in China and Southeast Asia is mainly the swamp buffalo and is used as draught animal. In China, ancient bones of Bubalus arnee have never been reported, and only one other extinct wild buffalo (Bubalus Mephistopheles) was identified in the Holocene. According to modern DNA analysis, the domestication of swamp buffalo occured earlier in Thailand than in China. Thus, the swamp buffalo would have been introduced from Southeast Asia (Yindee, 2010). However, when and where swamp buffalo was introduced into China remains unclear.
Until now, it has been difficult to differentiate swamp buffalo from wild buffalo (Bubalus Mephistopheles) if the horn was not found. Furthermore, DNA does not preserve well in ancient bones excavated from Southern China due to the acidic soil environment (Yang, et al., 2008). On the other hand, ZooMS analysis for bone collagen has been successfully applied to differentiate ancient animal species (Buckley and Collins, 2011). Thus, ZooMS could be used to differentiate buffalo bones between Bubalus Mephistopheles and swamp buffalo.
 Yang, Y., Bu, D., Zhao, X., Sun, P., Wang, J., Zhou, L., 2013. Proteomic analysis of cow, yak, buffalo, goat and camel milk whey proteins: quantitative differential expression patterns, Journal of proteome research 12, 1660-1667.
 Buckley, M., Collins, M.J., 2011. Collagen survival and its use for species identification in Holocene-lower Pleistocene bone fragments from British archaeological and paleontological sites, Antiqua 1, e1.
 Yindee, M., 2010. REPRODUCTION AND GENETIC DIVERSITY OF THE SWAMP BUFFALO, p. 63.
 Outram, A.K., Stear, N.A., Bendrey, R., Olsen, S., Kasparov, A., Zaibert, V., Thorpe, N., Evershed, R.P., 2009. The earliest horse harnessing and milking, Science 323, 1332-1335.
 Evershed, R.P., Payne, S., Sherratt, A.G., Copley, M.S., Coolidge, J., Urem-Kotsu, D., Kostas Kotsakis, M.Ö., gbreve, 2008. Earliest date for milk use in the Near East and southeastern Europe linked to cattle herding, NATURE 455, 528-531.
 Yang, D.Y., Liu, L., Chen, X., Speller, C.F., 2008. Wild or domesticated: DNA analysis of ancient water buffalo remains from north China, Journal of Archaeological Science 35, 2778-2785.
 Flad, R.K., Yuan, J., , Li, S., 2007. Zooarcheological evidence for animal domestication in northwest China, Developments in Quaternary Sciences 9, 167-203.
 Wiener, G., Han, J., Long, R., 2003. The Yak (2nd edtion), Bangkok: The Regional Office for Asia and the Pacific of the Food and Agriculture Organization of the United Nations.
 Olsen, S.J., 1990. Fossil ancestry of the yak, its cultural significance and domestication in Tibet, Proceedings of the Academy of Natural Sciences of Philadelphia, 73-100.