DataSheet1_Genetic structure and differentiation from early bronze age in the mediterranean island of sicily: Insights from ancient mitochondrial genomes.PDF

Sicily is one of the main islands of the Mediterranean Sea, and it is characterized by a variety of archaeological records, material culture and traditions, reflecting the history of migrations and populations’ interaction since its first colonization, during the Paleolithic. These deep and complex demographic and cultural dynamics should have affected the genomic landscape of Sicily at different levels; however, the relative impact of these migrations on the genomic structure and differentiation within the island remains largely unknown. The available Sicilian modern genetic data gave a picture of the current genetic structure, but the paucity of ancient data did not allow so far to make predictions about the level of historical variation. In this work, we sequenced and analyzed the complete mitochondrial genomes of 36 individuals from five different locations in Sicily, spanning from Early Bronze Age to Iron Age, and with different cultural backgrounds. The comparison with coeval groups from the Mediterranean Basin highlighted structured genetic variation in Sicily since Early Bronze Age, thus supporting a demic impact of the cultural transitions within the Island. Explicit model testing through Approximate Bayesian Computation allowed us to make predictions about the origin of Sicanians, one of the three indigenous peoples of Sicily, whose foreign origin from Spain, historically attributed, was not confirmed by our analysis of genetic data. Sicilian modern mitochondrial data show a different, more homogeneous, genetic composition, calling for a recent genetic replacement in the Island of pre-Iron Age populations, that should be further investigated.

西西里岛是地中海主要岛屿之一，其拥有丰富多样的考古记录、物质文化与传统，反映了自旧石器时代首次殖民以来的迁徙历史与人群互动状况。这些深刻且复杂的人口与文化动态，理应在不同层面塑造了西西里岛的基因组图景，但目前学界仍未明确这些迁徙对岛内部基因组结构与分化的相对影响。现有西西里现代遗传数据已勾勒出当前的遗传结构，但古代遗传数据的匮乏，使得学界迄今无法对历史层面的遗传变异水平作出推断。本研究对西西里5个不同地点的36份个体的完整线粒体基因组进行了测序与分析，样本时间跨度从青铜时代早期至铁器时代，且具有不同的文化背景。通过与地中海盆地同期群体的对比分析，本研究发现西西里自青铜时代早期便存在结构化的遗传变异，从而支持了岛内文化转型伴随有人群迁徙影响这一观点。借助近似贝叶斯计算（Approximate Bayesian Computation）开展的显式模型检验，我们对西西里三大土著族群之一的西卡尼人（Sicanians）的起源作出了推断：历史学界曾认为其起源自西班牙，但本研究的遗传数据分析未证实这一外来起源假说。西西里现代线粒体数据展现出更为均一的遗传组成，与古代样本存在显著差异，这表明铁器时代前的西西里岛人群曾经历近期的遗传更替，这一结论有待进一步研究验证。