Ancient Mitochondrial Genomes Reveal the Maternal Diversity and Genetic Influence of the Qijia Culture in Prehistoric Eastern Asia

OBJECTIVES: The Qijia culture (2300-1500 bce) in northwest China's Gansu-Qinghai region facilitated prehistoric exchanges between East Asia and the Eurasian steppe, yet its population origins and demographic dynamics remain unclear. We investigate the maternal genetic diversity, ancestry, and regional impact of the Qijia people to clarify their role in the prehistoric peopling of East Asia. MATERIALS AND METHODS: We analyzed 29 complete mitochondrial genomes from Qijia-associated individuals, comparing them with a comprehensive dataset of ancient and modern Eurasian populations using haplogroup assignment, phylogenetic analysis, and population genetic statistics. RESULTS: The Qijia population exhibits a dual ancestry structure, deriving from millet-farming groups from the Middle Yellow River (Shimao/Yangshao/Longshan cultures) and pastoralist populations from the Eastern Eurasian steppe. Notably, our analysis reveals little to no detectable contribution from Western Eurasia, despite archaeological evidence of cultural exchange. Key haplogroups, particularly F1g and D4j1b, link the Qijia people to modern Tibeto-Burman speakers (e.g., Tibetans and Qiangic groups), supporting a model of southward migration via the Tibetan-Yi Corridor. The presence of southern haplogroup F1a1a may indicate limited northward gene flow into the region. DISCUSSION: The Qijia culture likely served as a genetic "melting pot" and a subsequent source population, illustrating demographic processes that were distinct from mere cultural diffusion. Its dual origins reflect a convergence of agricultural expansion from the Central Plains and pastoralist movements from the north. Furthermore, its profound genetic connections to Tibeto-Burman groups highlight its enduring legacy in shaping the genetic landscape of modern populations in Southwest China.