RESUMO
We report genome-wide ancient DNA from 44 ancient Near Easterners ranging in time between ~12,000 and 1,400 bc, from Natufian hunter-gatherers to Bronze Age farmers. We show that the earliest populations of the Near East derived around half their ancestry from a 'Basal Eurasian' lineage that had little if any Neanderthal admixture and that separated from other non-African lineages before their separation from each other. The first farmers of the southern Levant (Israel and Jordan) and Zagros Mountains (Iran) were strongly genetically differentiated, and each descended from local hunter-gatherers. By the time of the Bronze Age, these two populations and Anatolian-related farmers had mixed with each other and with the hunter-gatherers of Europe to greatly reduce genetic differentiation. The impact of the Near Eastern farmers extended beyond the Near East: farmers related to those of Anatolia spread westward into Europe; farmers related to those of the Levant spread southward into East Africa; farmers related to those of Iran spread northward into the Eurasian steppe; and people related to both the early farmers of Iran and to the pastoralists of the Eurasian steppe spread eastward into South Asia.
Assuntos
Agricultura/história , Genômica , Migração Humana/história , Filogenia , Grupos Raciais/genética , África Oriental , Animais , Armênia , Ásia , DNA/análise , Europa (Continente) , História Antiga , Humanos , Hibridização Genética/genética , Irã (Geográfico) , Israel , Jordânia , Homem de Neandertal/genética , Filogeografia , TurquiaRESUMO
Britain and Ireland are known to show population genetic structure; however, large swathes of Scotland, in particular, have yet to be described. Delineating the structure and ancestry of these populations will allow variant discovery efforts to focus efficiently on areas not represented in existing cohorts. Thus, we assembled genotype data for 2,554 individuals from across the entire archipelago with geographically restricted ancestry, and performed population structure analyses and comparisons to ancient DNA. Extensive geographic structuring is revealed, from broad scales such as a NE to SW divide in mainland Scotland, through to the finest scale observed to date: across 3 km in the Northern Isles. Many genetic boundaries are consistent with Dark Age kingdoms of Gaels, Picts, Britons, and Norse. Populations in the Hebrides, the Highlands, Argyll, Donegal, and the Isle of Man show characteristics of isolation. We document a pole of Norwegian ancestry in the north of the archipelago (reaching 23 to 28% in Shetland) which complements previously described poles of Germanic ancestry in the east, and "Celtic" to the west. This modern genetic structure suggests a northwestern British or Irish source population for the ancient Gaels that contributed to the founding of Iceland. As rarer variants, often with larger effect sizes, become the focus of complex trait genetics, more diverse rural cohorts may be required to optimize discoveries in British and Irish populations and their considerable global diaspora.
Assuntos
DNA Antigo/análise , Etnicidade/genética , Variação Genética , Genética Populacional , Genoma Humano , Humanos , Irlanda , Ilhas , EscóciaRESUMO
The founder population of Newfoundland and Labrador (NL) is a unique genetic resource, in part due to its geographic and cultural isolation, where historical records describe a migration of European settlers, primarily from Ireland and England, to NL in the 18th and 19th centuries. Whilst its historical isolation, and increased prevalence of certain monogenic disorders are well appreciated, details of the fine-scale genetic structure and ancestry of the population are lacking. Understanding the genetic origins and background of functional, disease causing, genetic variants would aid genetic mapping efforts in the Province. Here, we leverage dense genome-wide SNP data on 1,807 NL individuals to reveal fine-scale genetic structure in NL that is clustered around coastal communities and correlated with Christian denomination. We show that the majority of NL European ancestry can be traced back to the south-east and south-west of Ireland and England, respectively. We date a substantial population size bottleneck approximately 10-15 generations ago in NL, associated with increased haplotype sharing and autozygosity. Our results reveal insights into the population history of NL and demonstrate evidence of a population conducive to further genetic studies and biomarker discovery.
Assuntos
Genética Populacional , População Branca , Humanos , Terra Nova e Labrador , Irlanda , Migração HumanaRESUMO
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RESUMO
The extent of population structure within Ireland is largely unknown, as is the impact of historical migrations. Here we illustrate fine-scale genetic structure across Ireland that follows geographic boundaries and present evidence of admixture events into Ireland. Utilising the 'Irish DNA Atlas', a cohort (n = 194) of Irish individuals with four generations of ancestry linked to specific regions in Ireland, in combination with 2,039 individuals from the Peoples of the British Isles dataset, we show that the Irish population can be divided in 10 distinct geographically stratified genetic clusters; seven of 'Gaelic' Irish ancestry, and three of shared Irish-British ancestry. In addition we observe a major genetic barrier to the north of Ireland in Ulster. Using a reference of 6,760 European individuals and two ancient Irish genomes, we demonstrate high levels of North-West French-like and West Norwegian-like ancestry within Ireland. We show that that our 'Gaelic' Irish clusters present homogenous levels of ancient Irish ancestries. We additionally detect admixture events that provide evidence of Norse-Viking gene flow into Ireland, and reflect the Ulster Plantations. Our work informs both on Irish history, as well as the study of Mendelian and complex disease genetics involving populations of Irish ancestry.
Assuntos
DNA/genética , Genética Populacional , Fluxo Gênico , Migração Humana , Humanos , IrlandaRESUMO
OBJECTIVE: To study the association between physicians' complaint records and their risk management experiences in a regional healthcare center. DATA SOURCES: Patient complaints about physicians in a large border state medical center's hospital and outpatient clinics were recorded and coded. The study period was from January 2001 through December 2003. These records were linked to the counterpart physicians' data covered by the institutions' risk management plan through June 2004. STUDY DESIGN AND DATA COLLECTION: All physicians at the institution who had contact with patients during the study period were identified as surgeons or non-surgeons. Complaints for these physicians were recorded by the institution's Office of Patient Relations (OPR) and independently coded using a standardized protocol to characterize the nature of the problem and to uniquely identify the person complained about. The complaint records were then linked to the risk management files (RMFs) for the defined physician cohort. In addition, these data were supplemented with clinical service values (RVUs) which were available for 338 members (76%) of the 445 member cohort. PRINCIPAL FINDINGS: Both patient complaints and risk management events were higher for surgeons than for non-surgeons. This was true for the number of RMFs, those involving expenditures, and for lawsuits. Logistic regression was used to assess the effects of complaint counts, practice type and volume of clinical activity. All were statistically significant in predicting the number of RMF openings, RMF openings with expenditures and lawsuits. Predictive concordance was 75% or greater for each of the three risk management outcomes. CONCLUSIONS: Expressions of patient dissatisfaction and practice type are significantly related to risk management experiences in a regional medical center. Associations of risk management experiences with volume of clinical activity (RVUs) for surgeons in the regional medical center environment were not as strong as those found in a similar study reported from an academic medical center.