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- Hunley, Keith, et al.
(författare)
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Genetic and Linguistic Coevolution in Northern Island Melanesia
- 2008
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Ingår i: PLOS Genetics. - : Public Library of Science (PLoS). - 1553-7390 .- 1553-7404. ; 4:10
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies have detailed a remarkable degree of genetic and linguistic diversity in Northern Island Melanesia. Here we utilize that diversity to examine two models of genetic and linguistic coevolution. The first model predicts that genetic and linguistic correspondences formed following population splits and isolation at the time of early range expansions into the region. The second is analogous to the genetic model of isolation by distance, and it predicts that genetic and linguistic correspondences formed through continuing genetic and linguistic exchange between neighboring populations. We tested the predictions of the two models by comparing observed and simulated patterns of genetic variation, genetic and linguistic trees, and matrices of genetic, linguistic, and geographic distances. The data consist of 751 autosomal microsatellites and 108 structural linguistic features collected from 33 Northern Island Melanesian populations. The results of the tests indicate that linguistic and genetic exchange have erased any evidence of a splitting and isolation process that might have occurred early in the settlement history of the region. The correlation patterns are also inconsistent with the predictions of the isolation by distance coevolutionary process in the larger Northern Island Melanesian region, but there is strong evidence for the process in the rugged interior of the largest island in the region (New Britain). There we found some of the strongest recorded correlations between genetic, linguistic, and geographic distances. We also found that, throughout the region, linguistic features have generally been less likely to diffuse across population boundaries than genes. The results from our study, based on exceptionally fine-grained data, show that local genetic and linguistic exchange are likely to obscure evidence of the early history of a region, and that language barriers do not particularly hinder genetic exchange. In contrast, global patterns may emphasize more ancient demographic events, including population splits associated with the early colonization of major world regions.
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| 2. |
- Morez, Adeline, et al.
(författare)
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Imputed genomes and haplotype-based analyses of the Picts of early medieval Scotland reveal fine-scale relatedness between Iron Age, early medieval and the modern people of the UK
- 2023
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Ingår i: PLOS Genetics. - : Public Library of Science (PLoS). - 1553-7390 .- 1553-7404. ; 19:4
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Tidskriftsartikel (refereegranskat)abstract
- There are longstanding questions about the origins and ancestry of the Picts of early medieval Scotland (ca. 300-900 CE), prompted in part by exotic medieval origin myths, their enigmatic symbols and inscriptions, and the meagre textual evidence. The Picts, first mentioned in the late 3(rd) century CE resisted the Romans and went on to form a powerful kingdom that ruled over a large territory in northern Britain. In the 9(th) and 10(th) centuries Gaelic language, culture and identity became dominant, transforming the Pictish realm into Alba, the precursor to the medieval kingdom of Scotland. To date, no comprehensive analysis of Pictish genomes has been published, and questions about their biological relationships to other cultural groups living in Britain remain unanswered. Here we present two high-quality Pictish genomes (2.4 and 16.5X coverage) from central and northern Scotland dated from the 5(th)-7(th) century which we impute and co-analyse with >8,300 previously published ancient and modern genomes. Using allele frequency and haplotype-based approaches, we can firmly place the genomes within the Iron Age gene pool in Britain and demonstrate regional biological affinity. We also demonstrate the presence of population structure within Pictish groups, with Orcadian Picts being genetically distinct from their mainland contemporaries. When investigating Identity-By-Descent (IBD) with present-day genomes, we observe broad affinities between the mainland Pictish genomes and the present-day people living in western Scotland, Wales, Northern Ireland and Northumbria, but less with the rest of England, the Orkney islands and eastern Scotland-where the political centres of Pictland were located. The pre-Viking Age Orcadian Picts evidence a high degree of IBD sharing across modern Scotland, Wales, Northern Ireland, and the Orkney islands, demonstrating substantial genetic continuity in Orkney for the last similar to 2,000 years. Analysis of mitochondrial DNA diversity at the Pictish cemetery of Lundin Links (n = 7) reveals absence of direct common female ancestors, with implications for broader social organisation. Overall, our study provides novel insights into the genetic affinities and population structure of the Picts and direct relationships between ancient and present-day groups of the UK.Author summary: We report two high-quality autosomal and eight mitochondrial genomes sequenced from individuals associated with the Pictish period of early medieval Scotland (ca. 300-900 CE). We demonstrate genetic affinities between the Pictish genomes and Iron Age people who lived in Britain, which supports current archaeological theories of a local origin. The autosomal genomes also allowed us to detect haplotype sharing between the Pictish genomes and present-day Europeans. Our results demonstrate a proportionally higher degree of haplotype sharing, and thus genetic affinity, between the Pictish genomes and individuals from western Scotland, Wales, Northern Ireland and Northumbria. We also detected genetic structure in Scotland during the Iron Age, likely driven by the combination of genetic drift and small population size, which we also detect in present-day Orcadians. Lastly, the seven mitochondrial DNA from the Lundin Links cemetery showed that these individuals had no direct maternal ancestors which could suggest exchanges of people, or at least females, between groups during the Pictish period, challenging older ideas that the Picts were a matrilineal society. Overall, our results show that high-quality ancient genomes combined with haplotype imputation are highly informative for obtaining novel insights to population structure and migration over the past 2,000 years.
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