Department of Integrative Biology, University of Texas, Austin, Texas, USA.
Department of Anthropology, University of Connecticut, Storrs, Connecticut, USA.
Am J Biol Anthropol. 2023 Jan;180(1):144-161. doi: 10.1002/ajpa.24638. Epub 2022 Nov 2.
This study aims to characterize the genetic histories of ancient hunter-gatherer groups in Fuego-Patagonia (Chile) with distinct Marine, Terrestrial, and Mixed Economy subsistence strategies. Mitochondrial (mtDNA) and Y-chromosome data were generated to test three hypotheses. H: All individuals were drawn from the same panmictic population; H: Terrestrial groups first populated the region and gave rise to highly specialized Marine groups by ~7,500 cal BP; or H: Marine and Terrestrial groups represent distinct ancestral lineages who migrated independently into the region.
Ancient DNA was extracted from the teeth of 50 Fuegian-Patagonian individuals dating from 6,895 cal BP to after European arrival, and analyzed alongside other individuals from previous studies. Individuals were assigned to Marine, Terrestrial, and Mixed Economy groups based on archeological context and stable isotope diet inferences, and mtDNA (HVR1/2) and Y-chromosome variation was analyzed.
Endogenous aDNA was obtained from 49/50 (98%) individuals. Haplotype diversities, F comparisons, and exact tests of population differentiation showed that Marine groups were significantly different from Terrestrial groups based on mtDNA (p < 0.05). No statistically significant differences were found between Terrestrial and Mixed Economy groups. Demographic simulations support models in which Marine groups diverged from the others by ~14,000 cal BP. Y-chromosome results showed similar patterns but were not statistically significant due to small sample sizes and allelic dropout.
These results support the hypothesis that Marine and Terrestrial economic groups represent distinct ancestral lineages who diverged during the time populations were expanding in the Americas, and may represent independent migrations into Fuego-Patagonia.
本研究旨在描述火地岛（智利）具有不同海洋、陆地和混合经济生计策略的古代狩猎采集群体的遗传历史。为了检验三个假说，我们生成了线粒体（mtDNA）和 Y 染色体数据。假说 H：所有个体都来自同一个混合群体；假说 H：陆地群体首先定居该地区，并在约 7500 年前产生了高度专业化的海洋群体；或假说 H：海洋和陆地群体代表不同的祖先群体，他们独立迁徙到该地区。
从古人类牙齿中提取了 50 名火地岛-巴塔哥尼亚个体的古 DNA，这些个体的年代从 6895 年前到欧洲人到达之后，同时还分析了来自之前研究的其他个体。根据考古背景和稳定同位素饮食推断，将个体分配到海洋、陆地和混合经济群体，分析了 mtDNA（HVR1/2）和 Y 染色体变异。
从 50 个个体中的 49 个（98%）获得了内源性 aDNA。单倍型多样性、F 比较和群体分化的精确检验表明，海洋群体在 mtDNA 上与陆地群体有显著差异（p<0.05）。陆地群体和混合经济群体之间没有发现统计学上的显著差异。人口统计学模拟支持海洋群体与其他群体在约 14000 年前分化的模型。Y 染色体结果显示出相似的模式，但由于样本量小和等位基因缺失，没有统计学意义。
这些结果支持了海洋和陆地经济群体代表不同祖先群体的假说，这些群体在美洲人口扩张期间发生了分化，可能代表了对火地岛的独立迁徙。
