Traces of Bronze Age globalization in East Asia: Insights from a revised phylogeography of the Y-chromosome haplogroup Q1a1a-M120

Objective: In this study, we aim to explore the genetic imprint of Bronze Age globalization in East Asia from a phylogeographic perspective by examining the Y-chromosome haplogroup Q1a1a-M120, and to identify key demographic processes involved in the formation of early China and the ancient Huaxia people. Methods: Over the past few decades, we have collected the sequences of 347 Y chromosomes from the haplogroup Q1a1a-M120. These sequences were utilized to analyze and reconstruct a highly revised phylogenetic tree with age estimates. And we analyzed the geographical distribution and spatial autocorrelation of nine major sub-branches of Q1a1a-M120. Finally, we observed the expansion of Q1a1a-M120 from the beginning of the Bronze Age in East Asia, along with the continuous dissemination of its sub-lineages among East Asian populations. Results: We suggest that certain sub-lineages played a significant role in the formation of states and early civilizations in China, as well as in the development of the ancient Huaxia people, who are the direct ancestors of the Han population. Overall, we propose that haplogroup Q-M120 played a role in the introduction of Bronze Age culture to the central region of East Asia. Therefore, it is haplogroup Q-M120, rather than the Western Eurasian paternal lineage, that expanded and contributed to the gene pool of the East Asian population. Conclusion: In summary, the globalization of the Bronze Age led to large-scale population replacement and admixture across various regions of Eurasia; our findings highlight the unique demographic processes that occurred in East Asia during this period.