Population Movement And Biological Adaptation At High Altitudes

加州大学默塞德分校的Mark Aldenderfer博士，沿着来自俄克拉荷马州大学、芝加哥大学和尼泊尔大学的同事们，将领导一个项目，探索高海拔环境如何影响人们的运动、物质文化、思想和基因。高海拔和高山峡谷是地球上最后被人类殖民的地方之一，这是由于缺氧、寒冷压力和资源相对稀缺的综合挑战。高山是人口流动和基因流动的障碍，往往在相距不远的山谷系统中造成文化、语言和遗传隔离。但最关键的是，高海拔环境需要遗传适应才能在其中成功永久居住。但是，在现代人群中增加这些基因频率的选择过程的古老性尚未得到解决;一些研究人员认为，由于强烈的自然选择，这些基因可以在人类群体中非常迅速地固定下来，而其他人则认为这个过程的发展要慢得多。考古学具有独特的优势，可以研究人类对这些极端环境的生物和文化适应，并研究文化和基因在时间过程中相互作用并受其影响的方式。Aldenderfer博士和他的团队将在尼泊尔上木斯塘的Kali Gandaki山谷研究文化、环境和基因随着时间的推移相互作用的方式。从历史上作为连接印度次大陆和西藏高原的主要贸易路线而闻名，该山谷似乎在大约3000年前首次被占领。虽然这些移民的地理来源是未知的，但有三个来源人群被假设：来自印度次大陆的人，来自西藏高原的人，最后，来自中亚的人通过西北喜马拉雅山脉。为了测试这些假设并确定促进适应高海拔生活的基因的古老性，研究人员将在关键的早期遗址进行挖掘，以恢复用于区域比较和人类遗骸的额外物质文化，从跨越山谷史前的三个考古时期的人类遗骸中提取古代DNA（aDNA）并进行基因分型，将这三个古老人群的基因组成与当代南亚人、东亚人和西欧人以及古代人类基因组进行比较，以测试有关该地区人口以及随后迁移到该地区的假设，最后，估计这些已知促进高海拔适应的古老种群中基因的频率，以测试这些基因随时间的系统性增加。 该项目将培训研究生和博士后研究员在本研究中开发的尖端aDNA提取和计算方法。研究人员还将与尼泊尔合作伙伴开展广泛的教育活动，包括在区域和地方博物馆展示项目成果，并与当地村庄领导人就如何保护和维护其文化遗产进行接触。

Dr. Mark Aldenderfer, of the University of California, Merced, along with colleagues from the University of Oklahoma, the University of Chicago, and Nepal, will lead a project to explore the ways in which high elevation environments affect the movement of people, material culture, ideas, and genes. High elevation and high mountain valleys were among the last places on the planet colonized by humans due to the combined challenges of hypoxia, cold stress, and the relative scarcity of resources found in them. High mountains act as barriers to population movement and gene flow and often create cultural, linguistic, and genetic isolates in valley systems that are only short distances apart. But most critically, high altitude environments require genetic adaptations for successful permanent habitation in them. But the antiquity of the selective processes that have increased the frequency of these genes in modern populations is unresolved; some researchers argue that these genes can become fixed very rapidly in human populations due to intense natural selection while others suggest the process develops much more slowly. Archaeology is uniquely positioned to study human biological and cultural adaptation to these extreme environments and to look at the ways in which culture and genes have interacted within and been affected by them over the course of time. Dr. Aldenderfer and his team will study the ways in which culture, environment, and genes have interacted over time in the Kali Gandaki valley of Upper Mustang, Nepal. Known from history as a key trade route that connected the Indian subcontinent to the Tibetan plateau, the valley appears to have been first occupied some 3000 years ago. While the geographic origin of these migrants is unknown, three source populations have been hypothesized: peoples from the Indian subcontinent, peoples from the Tibetan plateau, and finally, peoples from Central Asia via the northwestern Himalayas. To test these hypotheses and determine the antiquity of genes that promote adaptation to high elevation life, the researchers will conduct excavations at key early sites to recover additional material culture for regional comparisons and human remains, extract and genotype ancient DNA (aDNA) from the human remains from three archaeological periods that span the prehistory of the valley, compare the genetic make-up of these three ancient populations to contemporary South Asians, East Asians and Western Eurasians as well as archaic human genomes to test hypotheses about the peopling of the region as well as subsequent migrations into it, and finally, estimate the frequency of genes in these ancient populations known to promote high elevation adaptation to test for systematic increases in these genes over time. The project will train graduate students and postdoctoral fellows in the cutting edge aDNA extraction and computational methods developed in this research. The researchers will also foster a wide range of educational activities with their Nepali partners, including the development of displays of project findings in regional and local museums and engagement with local village leaders on how preserve and maintain their cultural heritage.