被譽為“世界屋脊”的青藏高原環(huán)境惡劣,，是人類較難以生存適應(yīng)的地區(qū)。但青藏高原上仍發(fā)掘出了較多舊石器,，表明該區(qū)域舊石器時期可能已經(jīng)有人類居住,。從考古資料來看，青藏高原上最主要的石器——細石器,，既有華北細石器的特點,，也承襲了一些當?shù)嘏f石器的特征，提示新石器時期的青藏高原人類很可能接受了當?shù)嘏f石器人類的文化上甚至遺傳上的影響,。
為系統(tǒng)研究藏族人群的起源,，在張亞平院士帶領(lǐng)下，博士生趙勉和孔慶鵬研究員等采集了覆蓋藏族在中國所有主要聚居地（西藏,、青海,、甘肅、四川及云南）的大量藏族人群樣本并對其母系遺傳結(jié)構(gòu)進行詳盡解析,。結(jié)果表明,，現(xiàn)代藏族人98％左右的母系遺傳組份均可追溯至新石器時期以來遷入青藏高原的中國北方人群，這與之前的遺傳研究結(jié)果及歷史記載相一致,。但值得注意的是,，研究也發(fā)現(xiàn)了一種稀有遺傳組份（類群M16）。與源自中國北方人群的母系遺傳組份不同的是,，M16直接從歐亞大陸建群類群M分化而來,，基本只能在藏族群體中觀測得到，且具有非常古老的分化年齡（>2.1萬年）,。對該結(jié)果最合理的解釋是,，M16很可能代表了舊石器晚期即已定居青藏高原的現(xiàn)代人類祖先延續(xù)至今的母系遺傳組份。
該研究提示，現(xiàn)代人類祖先在舊石器晚期即已克服惡劣的氣候及地理條件,，成功定居于青藏高原,，因而很好地解決了長期以來考古學、歷史學及遺傳學領(lǐng)域關(guān)于“人類最早何時成功定居于青藏高原”的爭論,。同時也從遺傳上進一步證實,，現(xiàn)今絕大多數(shù)藏族事實上源自新石器時期以來遷入青藏地區(qū)的中國北方人群。
研究結(jié)果近期發(fā)表在PNAS（《美國科學院院刊》）上,。（生物谷Bioon.com）
生物谷推薦原始出處：
PNAS December 2, 2009, doi: 10.1073/pnas.0907844106
Mitochondrial genome evidence reveals successful Late Paleolithic settlement on the Tibetan Plateau
Mian Zhaoa,b,1, Qing-Peng Konga,c,1,2, Hua-Wei Wangd, Min-Sheng Penga,b, Xiao-Dong Xiee, Wen-Zhi Wanga,b, Jiayangf, Jian-Guo Duang, Ming-Cui Caih, Shi-Neng Zhaoh, Cidanpingcuoi, Yuan-Quan Tuj, Shi-Fang Wua, Yong-Gang Yaok, Hans-Jürgen Bandeltl and Ya-Ping Zhanga,c,d,2
aState Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, Yunnan Province, China;
bGraduate School of the Chinese Academy of Sciences, Beijing 100049, China;
cKIZ/CUHK, Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming 650223, China;
dLaboratory for Conservation and Utilization of Bio-resource, Yunnan University, Kunming 650091, Yunnan Province, China;
eKey Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Science, Lanzhou University, Lanzhou 730000, Gansu Province, China;
fClinical Laboratory, People's Hospital of Shigatse Prefecture, Shigatse 857000, Tibet Autonomous Region, China;
gClinical Laboratory, People's Hospital of Nakchu Prefecture, Nakchu 852000, Tibet Autonomous Region, China;
hBlood Center of Liangshan Yi Autonomous Prefecture, Xichang 615000, Sichuan Province, China;
iBlood Center of Tibet, Lhasa 850000, Tibet Autonomous Region, China;
jYunnan Kunming Blood Center, Kunming 650106, Yunnan Province, China;
kKey Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; and
lDepartment of Mathematics, University of Hamburg, 20146 Hamburg, Germany
Due to its numerous environmental extremes, the Tibetan Plateau—the world's highest plateau—is one of the most challenging areas of modern human settlement. Archaeological evidence dates the earliest settlement on the plateau to the Late Paleolithic, while previous genetic studies have traced the colonization event(s) to no earlier than the Neolithic. To explore whether the genetic continuity on the plateau has an exclusively Neolithic time depth, we studied mitochondrial DNA (mtDNA) genome variation within 6 regional Tibetan populations sampled from Tibet and neighboring areas. Our results confirm that the vast majority of Tibetan matrilineal components can trace their ancestry to Epipaleolithic and Neolithic immigrants from northern China during the mid-Holocene. Significantly, we also identified an infrequent novel haplogroup, M16, that branched off directly from the Eurasian M founder type. Its nearly exclusive distribution in Tibetan populations and ancient age (>21 kya) suggest that M16 may represent the genetic relics of the Late Paleolithic inhabitants on the plateau. This partial genetic continuity between the Paleolithic inhabitants and the contemporary Tibetan populations bridges the results and inferences from archaeology, history, and genetics.
