Ancient genomic evidence of genetic integration among Xianbei populations in the Central Plains of China

The Xianbei tribe emerged as a dominant nomadic group on the eastern Eurasian steppe in the wake of Xiongnu's decline. Through warfare and waves of population movement, a branch of the Xianbei, known as the Tuoba Xianbei, established the Northern Wei Dynasty and relocated capital to Luoyang in the Central Plains of China. This relocation and the subsequent reforms under Emperor Xiaowen are traditionally framed as a top-down ‘Sinicization’ of Xianbei elites; however, historical and archaeological scholarship also emphasizes two-way interaction, in which Central Plains communities adopted (or negotiated) steppe-associated practices, institutions, and material culture. Historical records describe Sinicization and intermarriage policies, but the demographic consequences of these policies remain unclear. Ancient DNA provides a direct line of evidence to examine population interaction and genetic admixture, allowing us to move beyond textual accounts and assess the biological dimensions of this process of cultural transformation. Here, we present genome-wide data from an individual (M262) buried in Luoyang during the Northern Wei period in a tomb context archaeologically attributed to a Xianbei-associated elite. Genetically, M262 clusters with ancient and later populations from the Central Plains, indicating substantial local (Yellow River-related) ancestry. Taken together, these observations are compatible with at least two non-exclusive scenarios: (i) a person of Xianbei background who, through intermarriage and demographic integration after the move to Luoyang, carried predominantly local ancestry; and/or (ii) a person of local Central Plains ancestry who was socially incorporated into Xianbei-associated networks and expressed that affiliation through mortuary practice and material culture. By explicitly considering both possibilities, our study highlights that cultural identity and genetic ancestry need not coincide and provides a more cautious, empirically grounded view of population dynamics in northern China during the Northern Wei period.