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Published online: 16 December 2009 | Corrected online: 17 December 2009 | doi:10.1038/nchina.2009.236

Human evolution: Finding roots on the Tibetan Plateau

Felix Cheung

Introduction

© (2009) istockphoto.com/chunni4691

Qingpeng Kong and Yaping Zhang at the Chinese Academy of Sciences in Kunming and co-workers¹ have studied the mitochondrial DNA (mtDNA) genome variations in six regional Tibetan populations. They found that most of today's Tibetan people are descendents of Neolithic immigrants from northern China who settled on the Tibetan Plateau during the Holocene — a warmer period that continues to the present. More importantly, they identified an infrequent haplogroup that branched off directly from the Eurasian lineage. This novel haplogroup may represent the genetic relics of the Upper Palaeolithic immigrants who went to settle on the Tibetan Plateau more than 20 thousand years ago.

With its extreme environmental conditions and high altitudes, the Tibetan Plateau is probably the last place on Earth anyone would want to live. Nevertheless, archaeological evidence from a number of excavation sites has dated the earliest human settlement on the Tibetan Plateau to the Upper Palaeolithic — well before the last glacial period. Previous genetics studies, however, could only trace the ancestry of modern Tibetan people to the Neolithic.

The researchers recruited 680 individuals from six populations scattered across Tibet. They then sequenced the genome to look for mtDNAs that could reveal the maternal link to the ancient past. Most (653/680) of the individuals analysed had a Eurasian mtDNA lineage, and the majority (637/653) of those belonged to the East Asian haplogroup.

The researchers also identified M16, a novel haplogroup that branched off directly from the Eurasian lineage. Its nearly exclusive distribution in Tibetan populations and ancient age (> 21 thousand years ago) suggest that M16 may represent the genetic relics of the Upper Paleolithic inhabitants on the Tibetan Plateau.

The authors of this work are from:
State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China; Graduate University of Chinese Academy of Sciences, Beijing, China; KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming, China; Laboratory for Conservation and Utilization of Bio-resource, Yunnan University, Kunming, China; Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Science, Lanzhou University, Lanzhou, China; Clinical Laboratory, People's Hospital of Shigatse Prefecture, Shigatse, China; Clinical Laboratory, People's Hospital of Nakchu Prefecture, Nakchu, China; Blood Center of Liangshan Yi Autonomous Prefecture, Xichang, China; Blood Center of Tibet, Lhasa, China; Yunnan Kunming Blood Center, Kunming, China; Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China; Department of Mathematics, University of Hamburg, Hamburg, Germany.

Reference

1. Zhao, M. et al. Mitochondrial genome evidence reveals successful Late Paleolithic settlement on the Tibetan Plateau. Proc. Natl Acad. Sci. USA 106, 21230–21235 (2009).  | Article | OpenURL | | ChemPort |