Abstract: The West Liao River (WLR) and Yellow River (YR) basins are two major centers of millet farming in northern China. The result from flotation analyses and the spatial distribution of archeological sites indicate that two distinct survival strategies—agriculture and pastoralism were adopted in the southern and western regions of the WLR. Previous studies of ancient populations from the western area of the WLR suggested a correlation between a pastoral economy in the Bronze Age Upper Xiajiadian culture with a decreased genetic affinity with YR farmers. However, the population history of the southern WLR is unknown mainly due to the lack of ancient genetic data. Here we report the genomic data of an ancient individual from the Majiazishan site from the Late Bronze Age southern WLR region associated with Upper Xiajiadian culture. Unlike individuals from western WLR, this individual derived ancestry entirely from Late Neolithic YR farmers. We found a genetic substructure of the ancient human population of Upper Xiajiadian culture, which is consistent with the differences in the subsistence strategies of western and southern WLR. Climate deterioration led to different populations occupying the west and the south, respectively, in the WLR: the nomadic population from the Amur River (AR) in the west and the agricultural population from the YR in the south.

Key words: ancient DNA, climate change, Majiazishan, West Liao River, Yellow River