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[重要]兰大Science: 农业帮助人类于3600年前开始在青藏高原上实现永久定居

Science, 20 November 2014; DOI:10.1126/science.1259172


Agriculture facilitated permanent human occupation of the Tibetan Plateau after 3600 BP.
F. H. Chen, G. H. Dong, D. J. Zhang, X. Y. Liu, X. Jia, C. B. An, M. M. Ma, Y. W. Xie, L. Barton,X. Y. Ren, Z. J. Zhao, X. H. Wu, and M. K. Jones.

- Author Affiliations

1Key Laboratory of Western China’s Environmental Systems (Ministry of Education), Lanzhou University, Lanzhou 730000, China.
2McDonald Institute of Archaeological Research, University of Cambridge, Cambridge CB2 3ER, UK.
3Center for Comparative Archaeology, Department of Anthropology, University of Pittsburgh, Pittsburgh PA 15260, USA.
4Qinghai Provincial Institute of Cultural Relics and Archaeology, Xining 810007, China.
5Institute of Archaeology, Chinese Academy of Social Sciences, Beijing 100710, China.
6School of Archaeology and Museology, Peking University, Beijing 100871, China.
7The Interdisciplinary Program in Archaeology, Washington University in St. Louis, St. Louis MO 63130-48, USA.
↵*Corresponding author. E-mail: fhchen@lzu.edu.cn (F.H.C.); ghdong@lzu.edu.cn (G.H.D.)

ABSTRACT
    Our understanding of when and how humans adapted to living at altitudes above 2000 to 3000 meters of the Tibetan Plateau has been constrained by a paucity of archaeological data. Here we report data sets from the northeastern Tibetan Plateau indicating that the first villages were established only by 5200 years ago. Since 3600 calendar years before the present, a novel agropastoral economy facilitated year-round living at higher altitudes. This successful subsistence strategy facilitated the adaptation of farmers-herders to the challenges of global temperature decline during the late Holocene.

发表:http://www.sciencemag.org/conten ... cience.1259172.full
附件:http://www.sciencemag.org/conten ... 172.DC1/Chen.SM.pdf
正文:
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人类之子全都是为死而生。
              --------《阙特勤碑》
转自生物通:

http://www.bio360.net/news/show/12309.html

Science: 人类需要有大麦才能到达世界屋脊



    研究人员说,人们是在西方谷物-尤其是大麦到来时才在海拔3000米的西藏高原上建立永久居住地的。
       尽管有证据显示,人们在该地区的间歇性定居可追溯到至少2万年前,但Fahu Chen (陈发虎教授)和同事说,人们直到大约5200年前才在那里--即所谓的“世界屋脊”--站稳脚跟。而那些早期人类定居者只是在3600年前才知道如何在海拔3000英尺之上生存下来,因为他们说,当时一个跨越大陆的农作物移动给西藏高原带来了大麦、小麦及其它西方谷物。十分有趣的是,研究人员还提出,这一向上的迁徙发生在地球正在变冷的时候。


      Chen以及一个国际性研究小组对来自西藏高原东北地区各地的53处遗址的动物骨骼、植物遗骸及其它人工制品进行了研究,旨在描绘一幅该地区早期人类定居的画面。他们采样的大部分遗址代表了沿着黄河及其支流的早期农耕定居点。


      研究人员发现,这些最早人类定居主要是由小米——如狐尾粟和糜子——维持的,而它们仍然位于海拔2500米之下。他们说,接着,在大约3600年前,膳食大多由大麦组成的人类定居点开始向上移动至高达4700米的高度。


       研究人员提出,这些早期定居者可能是为搜寻猎物所驱而到西藏高原的--但调换成来自西方的主要农作物——它们比小米更耐寒——使得他们能在地球的屋脊建立永久性的家园。
人类之子全都是为死而生。
              --------《阙特勤碑》
转自网大:
http://bbs.netbig.com/thread-2674089-1-1.html
http://bbs.netbig.com/thread-2674196-1-1.html

来自兰州大学西部环境教育部重点实验室等处的研究人员发表了题为“Agriculture Facilitated Permanent Human Occupation of the Tibetan Plateau after 3,600 BP”的文章,通过对青藏高原东北地区各地的动物骨骼,植物遗骸及其它人工制品进行分析,指出大麦的出现是人类定居高海拔地区的一个环境条件,这将为更好的理解农作物演化,以及人类迁移提供重要的依据。

这一研究成果公布在11月21日Science杂志上。

农作物的演化对人类定居产生了重要的影响,如甘蔗糖的产生就直接导致了跨越洲际的人口大迁徙,而对于高原地区来说,种植物的变化也对当地人类定居产生了莫大的影响。

在这篇文章中,研究人员对来自青藏高原东北地区各地的53处遗址的动物骨骼、植物遗骸及其它人工制品进行了分析,发现自此大麦(Barley)产生后,人类就开始迁移到海拔高达4700米的地区定居

大麦是世界上最重要的粮食作物之一,这种植物碳水化合物含量较高,蛋白质、钙、磷含量中等,含少量B族维生素。因为大麦含谷蛋白(一种有弹性的蛋白质)量少,所以不能做多孔面包,可做不发酵食物,在北非及亚洲部分地区尤喜用大麦粉做麦片粥。

2012年Nature公布了大麦基因组测序图谱,构建了4.98 Gb的大麦基因组物理图谱,包括3.90 Gb高分辨率遗传图谱,研究人员用基因组鸟枪法装配和深度RNA测序等数据进行补充。研究确定了79,379个转录本,包括26,159个可信度高的基因。研究人员指出,大麦基因组中丰富的选择性剪切、提前终止密码子和新转录活性区域显示转录后剪切是重要的调控层面。

之前的研究表明人类是在大麦出现之后才能在海拔3000米的青藏高原上定居的,而这项最新研究则显示,人类大约是在5200年前才进入“世界屋脊”青藏高原定居下来。

此外这项研究还发现这一人类迁移事件发生在地球正在变冷的时期,研究人员通过对青藏高原东北地区各地动物骨骼、植物遗骸及其它人工制品分析,描绘了一幅该地区早期人类定居的画面。这些采样的大部分遗址代表了沿着黄河及其支流的早期农耕定居点

研究人员还发现,这些最早定居的人类主食为谷物,如小米和黍,而这些植物生长在海拔2500米之下,之后是随着时间的推移,大约在3600年前,定居者们的食物变成了大麦,这才开始再次向上迁移,达到海拔4700米的高度。

研究人员认为这些早期定居者可能是为了狩猎才来到青藏高原,但主食的变换,抗冻植物的出现帮助他们在此次定居了下来。
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人类之子全都是为死而生。
              --------《阙特勤碑》
报道所说的大麦,指的是青藏高原上的 青稞。 也就是说,青稞的培育是人类能够在 超过海拔2500米高度的地区实现长期定居的根本原因。

研究者所使用的证据极为丰富、过硬, 结果令人信服。
人类之子全都是为死而生。
              --------《阙特勤碑》
但他们的数据,对于研究汉藏群体分化来说,也是极为重要的。他们从考古证据看到的人群扩散,对应的就是遗传上和语言的群体分化。




配几张青稞的照片。
青稞海.jpg
高原植物----青稞.jpg
青稞2.jpg
人类之子全都是为死而生。
              --------《阙特勤碑》
Nature网站对文章的报道:
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SHARADA PRASAD/FLICKR


The introduction of cold-tolerant crops such as barley and wheat may have helped agriculture spread to the roof of the world.

By Lizzie Wade
20 November 2014 2:15 pm
2 Comments

Life above 3000 meters is tough. Not only can the thin air cause gasping and fatigue, but it can also swell brains and fill lungs with fluid, sometimes fatally. Yet people have been living at high altitudes for thousands of years in places like the Andes and the Tibetan Plateau. Now, a group of researchers believes it has identified a key tool that allowed Tibetans to settle at higher and higher elevations: barley.

The Tibetan Plateau, which encompasses the Himalaya Mountains and stretches across 2.5 million square kilometers, seems like a place that would have resisted human settlement. Yet archaeologists know that nomadic hunter-gatherers likely lived there seasonally and possibly year-round by at least 10,000 years ago. How and when agriculture—and the more settled lifestyle it requires—made its way to the higher reaches of the region remained mysterious. To begin to answer the question, a team of Chinese, American, and British researchers reviewed data from past excavations, some of which were conducted as far back as the 1970s. From 53 sites at various elevations and time periods, they managed to collect 63 samples of charred grains suitable for radiocarbon dating.

The new dates yielded an interesting pattern. Before 3600 years ago, farming appears to have been limited to 2500 meters and below. Far and away, the most abundant grain at these sites was millet, which had long been planted across northern China. Then, about 3600 years ago, farmers started climbing higher and higher up on the plateau, reaching as far as 3400 meters above sea level. So what changed?

The researchers think the plateau dwellers got their hands on some barley seeds. Compared with millet, barley is especially tolerant of cold and frost, making it ideal for high-elevation farming in Tibet, as Washington State University archaeologist Jade d’Alpoim Guedes pointed out in previous studies. And at right around 3600 years ago, barley starts showing up all over the Tibetan Plateau, sometimes accompanied by similarly cold-tolerant wheat. At lower elevations, plateau dwellers simply incorporated a bit of barley into their millet-heavy diet, but the high-altitude farmers appear to have abandoned millet altogether and relied almost completely on the new, hardier grain, the team reports online today inScience.

“Barley agriculture could provide people [with] sustained food supplies even during winter,” the three lead authors write in a joint e-mail. “Barley and wheat were first domesticated in [the Fertile Crescent] in West Asia around 10,500 years ago, where the environment is quite different from that in the Tibetan Plateau.” The fact that they thrived in the new, more extreme environment was “a lucky accident.” It’s unclear how and when barley moved from the Fertile Crescent to East Asia.

“It’s a fascinating example of a cultural strategy to tackle a challenging place,” says Kurt Rademaker, an archaeologist at the University of Tübingen in Germany who studies high-elevation settlements in the Andes. Interestingly, the expansion of farming to 3400-plus meters happened just as the climate in Tibet was getting colder—not optimal conditions for settling already chilly higher altitudes. But the barley seems to have made it so that “the climate was no longer a barrier,” Rademaker notes.

Still, agriculture may not have been required for year-round, permanent settlement of the Tibetan Plateau, says Mark Aldenderfer, an archaeologist at the University of California, Merced, who has excavated there for many years. “I think that the 3600-year-ago pulse [of human migration and settlement] is probably one of the very late migrations of people or ideas onto the plateau.” In fact, genetic studies suggest that Tibetans began to exhibit biological adaptions that helped them cope with high-altitude living at least 10,000 years ago, he notes.

But other genetic data suggests that at least one high-elevation gene appeared in Tibetans only between 2750 and 5500 years ago—more in line with the appearance of high-elevation agriculture on the plateau. “With disparate time estimates coming from the genetic studies, we need archaeological data to fix the chronology for when people are present in different places,” Rademaker says. High-elevation sites tend to be particularly difficult to study, so more information about them is “always valuable.”



Posted in Archaeology, Asia/Pacific, Biology, Plants & Animals


人类之子全都是为死而生。
              --------《阙特勤碑》
正文添加在 1#。
人类之子全都是为死而生。
              --------《阙特勤碑》
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