Arias Leonardo, Barbieri Chiara, Barreto Guillermo, Stoneking Mark, Pakendorf Brigitte
Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig D-04103, Germany.
Laboratorio de Genética Molecular Humana, Universidad del Valle, Cali, Colombia.
Am J Phys Anthropol. 2018 Feb;165(2):238-255. doi: 10.1002/ajpa.23345. Epub 2017 Oct 27.
Northwestern Amazonia (NWA) is a center of high linguistic and cultural diversity. Several language families and linguistic isolates occur in this region, as well as different subsistence patterns, with some groups being foragers and others agriculturalists. In addition, speakers of Eastern Tukanoan languages are known for practicing linguistic exogamy, a marriage system in which partners are taken from different language groups. In this study, we use high-resolution mitochondrial DNA sequencing to investigate the impact of this linguistic and cultural diversity on the genetic relationships and population structure of NWA groups.
We collected saliva samples from individuals representing 40 different NWA ethnolinguistic groups and sequenced 439 complete mitochondrial genomes to an average coverage of 1,030×.
The mtDNA data revealed that NWA populations have high genetic diversity with extensive sharing of haplotypes among groups. Moreover, groups who practice linguistic exogamy have higher genetic diversity, while the foraging Nukak have lower genetic diversity. We also find that rivers play a more important role than either geography or language affiliation in structuring the genetic relationships of populations.
Contrary to the view of NWA as a pristine area inhabited by small human populations living in isolation, our data support a view of high diversity and contact among different ethnolinguistic groups, with movement along rivers probably facilitating this contact. Additionally, we provide evidence for the impact of cultural practices, such as linguistic exogamy, on patterns of genetic variation. Overall, this study provides new data and insights into a remote and little-studied region of the world.
亚马孙西北部（NWA）是语言和文化高度多样的中心。该地区存在多个语系和语言孤立群体，以及不同的生存模式，一些群体以狩猎采集为生，另一些则从事农业。此外，东图卡诺语族的使用者以实行语言外婚制而闻名，这是一种伴侣来自不同语言群体的婚姻制度。在本研究中，我们使用高分辨率线粒体DNA测序来研究这种语言和文化多样性对NWA群体的遗传关系和种群结构的影响。
我们从代表40个不同NWA民族语言群体的个体中收集唾液样本，并对439个完整的线粒体基因组进行测序，平均覆盖度为1030倍。
线粒体DNA数据显示，NWA群体具有高度的遗传多样性，群体间单倍型广泛共享。此外，实行语言外婚制的群体具有更高的遗传多样性，而以狩猎采集为生的努卡克群体遗传多样性较低。我们还发现，在构建种群的遗传关系方面，河流比地理或语言归属发挥着更重要的作用。
与认为NWA是一个由孤立生活的小人群居住的原始地区的观点相反，我们的数据支持了不同民族语言群体之间具有高度多样性和接触的观点，沿着河流的迁移可能促进了这种接触。此外，我们提供了文化习俗（如语言外婚制）对遗传变异模式影响的证据。总体而言，本研究为这个世界上偏远且研究较少的地区提供了新的数据和见解。
