Most cited article - PubMed ID 31168094
Palaeo-Eskimo genetic ancestry and the peopling of Chukotka and North America
The North Eurasian forest and forest-steppe zones have sustained millennia of sociocultural connections among northern peoples, but much of their history is poorly understood. In particular, the genomic formation of populations that speak Uralic and Yeniseian languages today is unknown. Here, by generating genome-wide data for 180 ancient individuals spanning this region, we show that the Early-to-Mid-Holocene hunter-gatherers harboured a continuous gradient of ancestry from fully European-related in the Baltic, to fully East Asian-related in the Transbaikal. Contemporaneous groups in Northeast Siberia were off-gradient and descended from a population that was the primary source for Native Americans, which then mixed with populations of Inland East Asia and the Amur River Basin to produce two populations whose expansion coincided with the collapse of pre-Bronze Age population structure. Ancestry from the first population, Cis-Baikal Late Neolithic-Bronze Age (Cisbaikal_LNBA), is associated with Yeniseian-speaking groups and those that admixed with them, and ancestry from the second, Yakutia Late Neolithic-Bronze Age (Yakutia_LNBA), is associated with migrations of prehistoric Uralic speakers. We show that Yakutia_LNBA first dispersed westwards from the Lena River Basin around 4,000 years ago into the Altai-Sayan region and into West Siberian communities associated with Seima-Turbino metallurgy-a suite of advanced bronze casting techniques that expanded explosively from the Altai1. The 16 Seima-Turbino period individuals were diverse in their ancestry, also harbouring DNA from Indo-Iranian-associated pastoralists and from a range of hunter-gatherer groups. Thus, both cultural transmission and migration were key to the Seima-Turbino phenomenon, which was involved in the initial spread of early Uralic-speaking communities.
- MeSH
- Asian People * genetics MeSH
- White MeSH
- White People genetics MeSH
- History, Ancient MeSH
- Ethnicity * genetics MeSH
- Genome, Human genetics MeSH
- Haplotypes genetics MeSH
- Language * history MeSH
- Humans MeSH
- Chromosomes, Human, Y genetics MeSH
- Human Migration history MeSH
- Genetics, Population MeSH
- DNA, Ancient * analysis MeSH
- Check Tag
- History, Ancient MeSH
- Humans MeSH
- Male MeSH
- Publication type
- Journal Article MeSH
- Historical Article MeSH
- Geographicals
- Siberia ethnology MeSH
- Names of Substances
- DNA, Ancient * MeSH
BACKGROUND: Processes shaping the formation of the present-day population structure in highly urbanized Northern Europe are still poorly understood. Gaps remain in our understanding of when and how currently observable regional differences emerged and what impact city growth, migration, and disease pandemics during and after the Middle Ages had on these processes. RESULTS: We perform low-coverage sequencing of the genomes of 338 individuals spanning the eighth to the eighteenth centuries in the city of Sint-Truiden in Flanders, in the northern part of Belgium. The early/high medieval Sint-Truiden population was more heterogeneous, having received migrants from Scotland or Ireland, and displayed less genetic relatedness than observed today between individuals in present-day Flanders. We find differences in gene variants associated with high vitamin D blood levels between individuals with Gaulish or Germanic ancestry. Although we find evidence of a Yersinia pestis infection in 5 of the 58 late medieval burials, we were unable to detect a major population-scale impact of the second plague pandemic on genetic diversity or on the elevated differentiation of immunity genes. CONCLUSIONS: This study reveals that the genetic homogenization process in a medieval city population in the Low Countries was protracted for centuries. Over time, the Sint-Truiden population became more similar to the current population of the surrounding Limburg province, likely as a result of reduced long-distance migration after the high medieval period, and the continuous process of local admixture of Germanic and Gaulish ancestries which formed the genetic cline observable today in the Low Countries.
- Keywords
- Flanders, Low countries, Medieval, Migration, Palaeo-genomics, Plague, Urbanization,
- MeSH
- History, Medieval MeSH
- Genetic Variation MeSH
- Genome, Human MeSH
- Genomics MeSH
- Humans MeSH
- Plague epidemiology history genetics MeSH
- Genetics, Population MeSH
- Urbanization * history MeSH
- Check Tag
- History, Medieval MeSH
- Humans MeSH
- Publication type
- Journal Article MeSH
- Historical Article MeSH
- Geographicals
- Belgium MeSH
Elites played a pivotal role in the formation of post-Roman Europe on both macro- and microlevels during the Early Medieval period. History and archaeology have long focused on their description and identification based on written sources or through their archaeological record. We provide a different perspective on this topic by integrating paleogenomic, archaeological, and isotopic data to gain insights into the role of one such elite group in a Langobard period community near Collegno, Italy dated to the 6-8th centuries CE. Our analysis of 28 newly sequenced genomes together with 24 previously published ones combined with isotope (Sr, C, N) measurements revealed that this community was established by and organized around a network of biologically and socially related individuals likely composed of multiple elite families that over time developed into a single extended pedigree. The community also included individuals with diverse genetic ancestries, maintaining its diversity by integrating newcomers and groups in later stages of its existence. This study highlights how shifts in political power and migration impacted the formation and development of a small rural community within a key region of the former Western Roman Empire after its dissolution and the emergence of a new kingdom. Furthermore, it suggests that Early Medieval elites had the capacity to incorporate individuals from varied backgrounds and that these elites were the result of (political) agency rather than belonging to biologically homogeneous groups.
- Keywords
- burial archaeology, isotope, late antiquity, mobility, paleogenomics,
- MeSH
- Archaeology * MeSH
- History, Ancient MeSH
- History, Medieval MeSH
- Humans MeSH
- Human Migration history MeSH
- Roman World * history MeSH
- Check Tag
- History, Ancient MeSH
- History, Medieval MeSH
- Humans MeSH
- Publication type
- Journal Article MeSH
- Historical Article MeSH
- Geographicals
- Italy MeSH
f-statistics have emerged as a first line of analysis for making inferences about demographic history from genome-wide data. Not only are they guaranteed to allow robust tests of the fits of proposed models of population history to data when analyzing full genome sequencing data-that is, all single nucleotide polymorphisms (SNPs) in the individuals being analyzed-but they are also guaranteed to allow robust tests of models for SNPs ascertained as polymorphic in a population that is an outgroup in a phylogenetic sense to all groups being analyzed. True "outgroup ascertainment" is in practice impossible in humans because our species has arisen from a substructured ancestral population that does not descend from a homogeneous ancestral population going back many hundreds of thousands of years into the past. However, initial studies suggested that non-outgroup-ascertainment schemes might produce robust enough results using f-statistics, and that motivated widespread fitting of models to data using non-outgroup-ascertained SNP panels such as the "Affymetrix Human Origins array" which has been genotyped on thousands of modern individuals from hundreds of populations, or the "1240k" in-solution enrichment reagent which has been the source of about 70% of published genome-wide data for ancient humans. In this study, we show that while analyses of population history using such panels work well for studies of relationships among non-African populations and one African outgroup, when co-modeling more than one sub-Saharan African and/or archaic human groups (Neanderthals and Denisovans), fitting of f-statistics to such SNP sets is expected to frequently lead to false rejection of true demographic histories, and failure to reject incorrect models. Analyzing panels of SNPs polymorphic in archaic humans, which has been suggested as a solution for the ascertainment problem, has limited statistical power and retains important biases. However, by carrying out simulations of diverse demographic histories, we show that bias in inferences based on f-statistics can be minimized by ascertaining on variants common in a union of diverse African groups; such ascertainment retains high statistical power while allowing co-analysis of archaic and modern groups.
- MeSH
- African People * genetics MeSH
- Biological Variation, Population genetics MeSH
- Black People genetics MeSH
- Demography * history MeSH
- Phylogeny * MeSH
- Genotype MeSH
- Polymorphism, Single Nucleotide * genetics MeSH
- Humans MeSH
- Chromosome Mapping MeSH
- Neanderthals genetics MeSH
- Models, Statistical MeSH
- Bias MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
Our understanding of population history in deep time has been assisted by fitting admixture graphs (AGs) to data: models that specify the ordering of population splits and mixtures, which along with the amount of genetic drift and the proportions of mixture, is the only information needed to predict the patterns of allele frequency correlation among populations. The space of possible AGs relating populations is vast, and thus most published studies have identified fitting AGs through a manual process driven by prior hypotheses, leaving the majority of alternative models unexplored. Here, we develop a method for systematically searching the space of all AGs that can incorporate non-genetic information in the form of topology constraints. We implement this findGraphs tool within a software package, ADMIXTOOLS 2, which is a reimplementation of the ADMIXTOOLS software with new features and large performance gains. We apply this methodology to identify alternative models to AGs that played key roles in eight publications and find that in nearly all cases many alternative models fit nominally or significantly better than the published one. Our results suggest that strong claims about population history from AGs should only be made when all well-fitting and temporally plausible models share common topological features. Our re-evaluation of published data also provides insight into the population histories of humans, dogs, and horses, identifying features that are stable across the models we explored, as well as scenarios of populations relationships that differ in important ways from models that have been highlighted in the literature.
- Keywords
- admixture graphs, dogs, evolutionary biology, f-statistics, genetics, genomics, horses, human, humans, population genetics,
- MeSH
- Gene Frequency MeSH
- Genetic Drift MeSH
- Hominidae * MeSH
- Horses MeSH
- Humans MeSH
- Models, Genetic MeSH
- Genetics, Population * MeSH
- Dogs MeSH
- Software MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Dogs MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
Thailand is a country where over 60 languages from five language families (Austroasiatic, Austronesian, Hmong-Mien, Kra-Dai, and Sino-Tibetan) are spoken. The Kra-Dai language family is the most prevalent, and Thai, the official language of the country, belongs to it. Previous genome-wide studies on Thailand populations revealed a complex population structure and put some hypotheses forward concerning the population history of the country. However, many published populations have not been co-analyzed, and some aspects of population history were not explored adequately. In this study, we employ new methods to re-analyze published genome-wide genetic data on Thailand populations, with a focus on 14 Kra-Dai-speaking groups. Our analyses reveal South Asian ancestry in Kra-Dai-speaking Lao Isan and Khonmueang, and in Austroasiatic-speaking Palaung, in contrast to a previous study in which the data were generated. We support the admixture scenario for the formation of Kra-Dai-speaking groups from Thailand who harbor both Austroasiatic-related ancestry and Kra-Dai-related ancestry from outside of Thailand. We also provide evidence of bidirectional admixture between Southern Thai and Nayu, an Austronesian-speaking group from Southern Thailand. Challenging some previously reported genetic analyses, we reveal a close genetic relationship between Nayu and Austronesian-speaking groups from Island Southeast Asia (ISEA).
- MeSH
- Asian * ethnology genetics MeSH
- Asian People * ethnology genetics MeSH
- Genome-Wide Association Study MeSH
- Language * MeSH
- Humans MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Asia, Southeastern ethnology MeSH
- Thailand MeSH
The great ethnolinguistic diversity found today in mainland Southeast Asia (MSEA) reflects multiple migration waves of people in the past. Maritime trading between MSEA and India was established at the latest 300 BCE, and the formation of early states in Southeast Asia during the first millennium CE was strongly influenced by Indian culture, a cultural influence that is still prominent today. Several ancient Indian-influenced states were located in present-day Thailand, and various populations in the country are likely to be descendants of people from those states. To systematically explore Indian genetic heritage in MSEA populations, we generated genome-wide SNP data (using the Affymetrix Human Origins array) for 119 present-day individuals belonging to 10 ethnic groups from Thailand and co-analyzed them with published data using PCA, ADMIXTURE, and methods relying on f-statistics and on autosomal haplotypes. We found low levels of South Asian admixture in various MSEA populations for whom there is evidence of historical connections with the ancient Indian-influenced states but failed to find this genetic component in present-day hunter-gatherer groups and relatively isolated groups from the highlands of Northern Thailand. The results suggest that migration of Indian populations to MSEA may have been responsible for the spread of Indian culture in the region. Our results also support close genetic affinity between Kra-Dai-speaking (also known as Tai-Kadai) and Austronesian-speaking populations, which fits a linguistic hypothesis suggesting cladality of the two language families.
- MeSH
- Asian People genetics MeSH
- Ethnicity genetics MeSH
- Genetic Variation genetics MeSH
- Haplotypes genetics MeSH
- Language MeSH
- Polymorphism, Single Nucleotide genetics MeSH
- Humans MeSH
- Genetics, Population methods MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
- Geographicals
- India ethnology MeSH
- Asia, Southeastern ethnology MeSH
- Thailand ethnology MeSH