The formation of human populations in South and Central Asia

Heterogeneity of the Southeast Belarusian mitochondrial gene pool

The study of mitochondrial DNA (mtDNA) variability at the level of whole mitogenomes has significant implications for the fields of human evolution and population genetics. In this paper, we present the results of a study of the complete mtDNA variability in Belarusians from the southeastern part of the Republic of Belarus. It was found that Southeast Belarusians are characterized by a high diversity of mitochondrial genomes. The analysis of genetic distances between European populations showed significant differences between the studied Belarusian sample from the bulk of East European populations, including Slavic ethnic groups. The results of the phylogeographic analysis indicated the presence of the West Asian component (12.6%) in the Belarusian mitochondrial gene pool, which can account for the observed genetic differences between Belarusians and other Eastern Slavs (Russians and Ukrainians). The East Asian component of the mitochondrial gene pool of the studied group of Belarusians is represented by haplogroup C5c1a (2.3%). The results of the phylogeographic analysis indicated that this mtDNA subclade is predominantly present in the gene pools of Slavic peoples, including Poles, Belarusians, Ukrainians, and Russians. The evolutionary age of haplogroup C5c1a is ~4000 years and, consequently, the appearance of C5c1-haplotypes in the eastern regions of Europe may be linked to the migrations of the Caspian steppe populations to the west during the Bronze Age.

A probabilistic approach to visualize the effect of missing data on PCA in ancient human genomics

BACKGROUND

Principal Component Analysis (PCA) is widely used in population genetics to visualize genetic relationships and population structures. In ancient genomics, genotype information may in parts remain unresolved due to the low abundance and degraded quality of ancient DNA. While methods like SmartPCA allow the projection of ancient samples despite missing data, they do not quantify projection uncertainty. The reliability of PCA projections for often very sparse ancient genotype samples is not well understood. Ignoring this uncertainty may lead to overconfident conclusions about the observed genetic relationships and population structure.

RESULTS

This study systematically investigates the impact of missing loci on PCA projections using both simulated and real ancient human genotype data. Through extensive simulations with high-coverage ancient samples, we demonstrate that increasing levels of missing data can lead to less accurate SmartPCA projections, highlighting the importance of considering uncertainty when interpreting PCA results from ancient samples. To address this, we developed a probabilistic framework to quantify the uncertainty in PCA projections due to missing data. By applying our methodology to modern and ancient West Eurasian genotype samples from the Allen Ancient DNA Resource database, we could show a high concordance between our predicted projection and empirically derived distributions. Applying this framework to real-world data, we demonstrate its utility in predicting and visualizing embedding uncertainties for ancient samples of varying SNP coverages.

CONCLUSION

Our results emphasize the importance of accounting for projection uncertainty in ancient population studies. We therefore make our probabilistic model available through TrustPCA, a user-friendly web tool that provides researchers with uncertainty estimates alongside PCA projections, facilitating data exploration in ancient human genomic studies and enhancing transparency in data quality reporting.

Urbanization and genetic homogenization in the medieval Low Countries revealed through a ten-century paleogenomic study of the city of Sint-Truiden

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.

Performance of qpAdm-based screens for genetic admixture on graph-shaped histories and stepping stone landscapes

qpAdm is a statistical tool that is often used for testing large sets of alternative admixture models for a target population. Despite its popularity, qpAdm remains untested on 2D stepping stone landscapes and in situations with low prestudy odds (low ratio of true to false models). We tested high-throughput qpAdm protocols with typical properties such as number of source combinations per target, model complexity, model feasibility criteria, etc. Those protocols were applied to admixture graph-shaped and stepping stone simulated histories sampled randomly or systematically. We demonstrate that false discovery rates of high-throughput qpAdm protocols exceed 50% for many parameter combinations since: (1) prestudy odds are low and fall rapidly with increasing model complexity; (2) complex migration networks violate the assumptions of the method; hence, there is poor correlation between qpAdm P-values and model optimality, contributing to low but nonzero false-positive rate and low power; and (3) although admixture fraction estimates between 0 and 1 are largely restricted to symmetric configurations of sources around a target, a small fraction of asymmetric highly nonoptimal models have estimates in the same interval, contributing to the false-positive rate. We also reinterpret large sets of qpAdm models from 2 studies in terms of source-target distance and symmetry and suggest improvements to qpAdm protocols: (1) temporal stratification of targets and proxy sources in the case of admixture graph-shaped histories, (2) focused exploration of few models for increasing prestudy odds; and (3) dense landscape sampling for increasing power and stringent conditions on estimated admixture fractions for decreasing the false-positive rate.

Unique demographic history and population substructure among the Coorgs of Southern India

The fascinating genetic architecture of today's Indian population is the result of thousands of years of population mixing and eventual isolation. The Coorgs are one such small and religiously/socioculturally homogeneous community in Karnataka, India, whose origins and demographic history are much debated due to their stark sociocultural contrast with surrounding populations. Here, we analyzed Coorgs using both autosomal (n = 70) and uniparental markers (n = 144). Our analyses suggest population substructure among Coorgs and showed significant population drift in Coorg3 in both allele frequency and haplotype-based analysis methods. Further sharing of haplotype and identity by descent suggests a shared genetic history of Coorg1 with the Palliyar population, and founder event analysis clearly indicates that the founder event in Coorg1 was around 40 GBP (Generations Before Present). The demographic models based on fastGlobeTrotter and Moments highlighted the recent admixture of Coorg3 with the northwest Indian Sikh Jatt population (~23 GBP); and also showed that Coorg2 was formed by mixing Coorg1 and Coorg3 at ~11 GBP, explaining their current sociocultural homogeneity. F-statistics-based admixture graph models suggest an as yet unknown lineage in Coorg3. mtDNA analysis revealed about 40% South Asia-specific mitochondrial lineages in Coorgs; while Y chromosome analysis revealed a predominance of Eurasian, Middle Eastern, and Indian-specific haplogroups, suggesting male-mediated migration and eventual assimilation with native females. These insights into ancient and diverse genealogies among Coorgs not only explain their unique status in the Indian diaspora but also encourage further research to identify unknown migrations to the Indian subcontinent and thus further unravel its unique demography.

Ancient DNA from the Green Sahara reveals ancestral North African lineage

Although it is one of the most arid regions today, the Sahara Desert was a green savannah during the African Humid Period (AHP) between 14,500 and 5,000 years before present, with water bodies promoting human occupation and the spread of pastoralism in the middle Holocene epoch1. DNA rarely preserves well in this region, limiting knowledge of the Sahara's genetic history and demographic past. Here we report ancient genomic data from the Central Sahara, obtained from two approximately 7,000-year-old Pastoral Neolithic female individuals buried in the Takarkori rock shelter in southwestern Libya. The majority of Takarkori individuals' ancestry stems from a previously unknown North African genetic lineage that diverged from sub-Saharan African lineages around the same time as present-day humans outside Africa and remained isolated throughout most of its existence. Both Takarkori individuals are closely related to ancestry first documented in 15,000-year-old foragers from Taforalt Cave, Morocco2, associated with the Iberomaurusian lithic industry and predating the AHP. Takarkori and Iberomaurusian-associated individuals are equally distantly related to sub-Saharan lineages, suggesting limited gene flow from sub-Saharan to Northern Africa during the AHP. In contrast to Taforalt individuals, who have half the Neanderthal admixture of non-Africans, Takarkori shows ten times less Neanderthal ancestry than Levantine farmers, yet significantly more than contemporary sub-Saharan genomes. Our findings suggest that pastoralism spread through cultural diffusion into a deeply divergent, isolated North African lineage that had probably been widespread in Northern Africa during the late Pleistocene epoch.

High continuity of forager ancestry in the Neolithic period of the eastern Maghreb

Ancient DNA from the Mediterranean region has revealed long-range connections and population transformations associated with the spread of food-producing economies1-6. However, in contrast to Europe, genetic data from this key transition in northern Africa are limited, and have only been available from the far western Maghreb (Morocco)1-3. Here we present genome-wide data for nine individuals from the Later Stone Age through the Neolithic period from Algeria and Tunisia. The earliest individuals cluster with pre-Neolithic people of the western Maghreb (around 15,000-7,600 years before present (BP)), showing that this 'Maghrebi' ancestry profile had a substantial geographic and temporal extent. At least one individual from Djebba (Tunisia), dating to around 8,000 years BP, harboured ancestry from European hunter-gatherers, probably reflecting movement in the Early Holocene across the Strait of Sicily. Later Neolithic people from the eastern Maghreb retained largely local forager ancestry, together with smaller contributions from European farmers (by around 7,000 years BP) and Levantine groups (by around 6,800 years BP), and were thus far less impacted by external gene flow than were populations in other parts of the Neolithic Mediterranean.

Rocks and clay: Potters' technological choices within the cultural dynamics of Bronze Age Kazakhstan

Through regular interactions with their neighbors, diverse groups inhabiting areas along the Inner Asian Mountain Corridor during the Bronze Age formed dynamic interregional networks that saw the proliferation and persistence of shared material cultures over vast geographic areas. In this paper we advocate for ceramics analyses that combine both macro- and micro-scale technological studies alongside those of style, in order not to lose sight of the actual people who drove defining transformations in the Bronze Age. We present a petrographic study of pottery from the Zhetysu region, southeastern Kazakhstan, to examine diachronic technological traditions with a special focus on routines of selection and raw material processing. Our results demonstrate site-specific potting technologies as well as traits that transcend both time and space across episodes of high genetic turnover in the human population.

Ancient genomes reveal trans-Eurasian connections between the European Huns and the Xiongnu Empire

The Huns appeared in Europe in the 370s, establishing an Empire that reshaped West Eurasian history. Yet until today their origins remain a matter of extensive debate. Traditional theories link them to the Xiongnu, the founders of the first nomadic empire of the Mongolian steppe. The Xiongnu empire dissolved, however, ~300 y before the Huns appeared in Europe, and there is little archaeological and historical evidence of Huns in the steppe during this time gap. Furthermore, despite the rich 5th to 6th centuries current era (CE) archaeological record of the Carpathian Basin, the cultural elements of connections with the steppe are limited to few findings and even fewer solitary eastern-type burials. In this study, we coanalyze archaeological evidence with 35 newly sequenced and published genomic data for a total of 370 individuals-from 5th to 6th century CE contexts in the Carpathian Basin including 10 Hun-period eastern-type burials, 2nd to 5th century sites across Central Asia and 2nd c. before current era (BCE) to 1st c. CE Xiongnu period sites across the Mongolian steppe. We find no evidence for the presence of a large eastern/steppe descent community among the Hun- and post-Hun-period Carpathian Basin population. We also observe a high genetic diversity among the eastern-type burials that recapitulates the variability observed across the Eurasian Steppe. This suggests a mixed origin of the incoming steppe conquerors. Nevertheless, long-shared genomic tracts provide compelling evidence of genetic lineages directly connecting some individuals of the highest Xiongnu-period elite with 5th to 6th century CE Carpathian Basin individuals, showing that some European Huns descended from them.

Exploring the genetic implications of demographic dynamics in Jammu and Kashmir using autosomal STRs

The Union Territory of Jammu and Kashmir has always been a point of contention among India, Pakistan, and China for various reasons. This region has great significance historically due to its geography and ethnic diversity. However, a comprehensive genetic study providing the genetic landscape of Jammu and Kashmir was lacking until now. In this study, we analysed 21 hyper-variable autosomal STR loci of 694 individuals from Jammu and Kashmir and compared them with neighbouring populations to explore the genetic implications of demographic dynamics that have taken place in this region. Our findings suggest that the population of Jammu and Kashmir is a genetic mixture of two major clines, northern and southern, that correspond with the variation in geography, linguistics, and demography of the region. Broadly, the gene flow into the southern cline appears to be in historical times perhaps as a result of the spread of Gurjars, Dogri language and invasions of Mongols. However, the arrival of ancient nomadic tribes into this region may belong to the time depth of the arrival of pastoralist communities in this region. As a future perspective, a comprehensive study including samples from individual tribes will provide fine-scale structure of the gene pool of Jammu and Kashmir.

A genomic history of the North Pontic Region from the Neolithic to the Bronze Age

The North Pontic Region was the meeting point of the farmers of Old Europe and the foragers and pastoralists of the Eurasian steppe1,2, and the source of migrations deep into Europe3-5. Here we report genome-wide data from 81 prehistoric North Pontic individuals to understand the genetic makeup of its people. North Pontic foragers had ancestry from Balkan and Eastern hunter-gatherers6 as well as European farmers and, occasionally, Caucasus hunter-gatherers. During the Eneolithic period, a wave of migrants from the Caucasus-Lower Volga area7 bypassed local foragers to mix in equal parts with Trypillian farmers, forming the people of the Usatove culture around 4500 BCE. A temporally overlapping wave of migrants from the Caucasus-Lower Volga blended with foragers instead of farmers to form Serednii Stih people7. The third wave was the Yamna-descendants of the Serednii Stih who formed by mixture around 4000 BCE and expanded during the Early Bronze Age (3300 BCE). The temporal gap between Serednii Stih and the Yamna is bridged by a genetically Yamna individual from Mykhailivka, Ukraine (3635-3383 BCE), a site of archaeological continuity across the Eneolithic-Bronze Age transition and a likely epicentre of Yamna formation. Each of these three waves of migration propagated distinctive ancestries while also incorporating outsiders, a flexible strategy that may explain the success of the peoples of the North Pontic in spreading their genes and culture across Eurasia3-5,8-10.

The genetic origin of the Indo-Europeans

The Yamnaya archaeological complex appeared around 3300 BC across the steppes north of the Black and Caspian Seas, and by 3000 BC it reached its maximal extent, ranging from Hungary in the west to Kazakhstan in the east. To localize Yamnaya origins among the preceding Eneolithic people, we assembled ancient DNA from 435 individuals, demonstrating three genetic clines. A Caucasus-lower Volga (CLV) cline suffused with Caucasus hunter-gatherer1 ancestry extended between a Caucasus Neolithic southern end and a northern end at Berezhnovka along the lower Volga river. Bidirectional gene flow created intermediate populations, such as the north Caucasus Maikop people, and those at Remontnoye on the steppe. The Volga cline was formed as CLV people mixed with upriver populations of Eastern hunter-gatherer2 ancestry, creating hypervariable groups, including one at Khvalynsk. The Dnipro cline was formed when CLV people moved west, mixing with people with Ukraine Neolithic hunter-gatherer ancestry3 along the Dnipro and Don rivers to establish Serednii Stih groups, from whom Yamnaya ancestors formed around 4000 BC and grew rapidly after 3750-3350 BC. The CLV people contributed around four-fifths of the ancestry of the Yamnaya and, entering Anatolia, probably from the east, at least one-tenth of the ancestry of Bronze Age central Anatolians, who spoke Hittite4,5. We therefore propose that the final unity of the speakers of 'proto-Indo-Anatolian', the language ancestral to both Anatolian and Indo-European people, occurred in CLV people some time between 4400 BC and 4000 BC.

Admixture as a source for HLA variation in Neolithic European farming communities

BACKGROUND

The northern European Neolithic is characterized by two major demographic events: immigration of early farmers from Anatolia at 7500 years before present, and their admixture with local western hunter-gatherers forming late farmers, from around 6200 years before present. The influence of this admixture event on variation in the immune-relevant human leukocyte antigen (HLA) region is understudied.

RESULTS

We analyzed genome-wide data of 125 individuals from seven archeological early farmer and late farmer sites located in present-day Germany. The late farmer group studied here is associated with the Wartberg culture, from around 5500-4800 years before present. We note that late farmers resulted from sex-biased admixture from male western hunter-gatherers. In addition, we observe Y-chromosome haplogroup I as the dominant lineage in late farmers, with site-specific sub-lineages. We analyze true HLA genotypes from 135 Neolithic individuals, the majority of which were produced in this study. We observe significant shifts in HLA allele frequencies from early farmers to late farmers, likely due to admixture with western hunter-gatherers. Especially for the haplotype DQB1*04:01-DRB1*08:01, there is evidence for a western hunter-gatherer origin. The HLA diversity increased from early farmers to late farmers. However, it is considerably lower than in modern populations.

CONCLUSIONS

Both early farmers and late farmers exhibit a relatively narrow HLA allele spectrum compared to today. This coincides with sparse traces of pathogen DNA, potentially indicating a lower pathogen pressure at the time.

East and West admixture in eastern China of Tang Dynasty inferred from ancient human genomes

The ancestry composition and Sinicisation process of the descendants of the immigrants of Hu people living in ancient China are largely unknown due to the lack of genetic evidence. Tang Dynasty people in Fudamen cemetery () excavated from Shandong province in eastern China are believed to be related to the descendants of Hu people, as some of the individuals with the surnames An (). The genetic origin of the Fudamen population requires genetic clarification using ancient DNA data. Here we successfully obtain genome-wide SNP data for 17 Tang dynasty individuals from Fudamen cemetery. Based on autosomal data, although all Fudamen individuals show high levels of middle reaches of Yellow River-related ancestry as previously published historical period Shandong populations, 2 Fudamen individuals require ~5% Western Eurasian/Central Asian-related ancestry to describe their ancestry composition best. To the best of our knowledge, it is the first evidence of such ancestry in Shandong, the eastern part of today's China. Moreover, the admixture pattern is also reflected by the presence of both west and east Eurasian-specific mtDNA and Y chromosomal haplogroups in Fudamen people. The estimated admixture time is also consistent with periods when Sogdians and other non-Han populations were active in ancient China. These genomic findings suggest that intermarriage with Han Chinese involved the Sinicization process of the Hu people.

PANE: fast and reliable ancestral reconstruction on ancient genotype data with non-negative least square and principal component analysis

The history of human populations has been strongly shaped by admixture events, contributing to patterns of observed genetic diversity across populations. In this study, we introduce the Principal component Ancestry proportions using NNLS Estimation (PANE) method that leverages principal component analysis and non-negative least squares to assess the ancestral compositions of admixed individuals given a large set of populations. Our results show its ability to reliably estimate ancestry across several scenarios, even those with a significant proportion of missing genotypes, in a fraction of the time required when using other tools.

Performance of qpAdm-based screens for genetic admixture on admixture-graph-shaped histories and stepping-stone landscapes

qpAdm is a statistical tool that is often used for testing large sets of alternative admixture models for a target population. Despite its popularity, qpAdm remains untested on two-dimensional stepping-stone landscapes and in situations with low pre-study odds (low ratio of true to false models). We tested high-throughput qpAdm protocols with typical properties such as number of source combinations per target, model complexity, model feasibility criteria, etc. Those protocols were applied to admixture-graph-shaped and stepping-stone simulated histories sampled randomly or systematically. We demonstrate that false discovery rates of high-throughput qpAdm protocols exceed 50% for many parameter combinations since: 1) pre-study odds are low and fall rapidly with increasing model complexity; 2) complex migration networks violate the assumptions of the method, hence there is poor correlation between qpAdm p-values and model optimality, contributing to low but non-zero false positive rate and low power; 3) although admixture fraction estimates between 0 and 1 are largely restricted to symmetric configurations of sources around a target, a small fraction of asymmetric highly non-optimal models have estimates in the same interval, contributing to the false positive rate. We also re-interpret large sets of qpAdm models from two studies in terms of source-target distance and symmetry and suggest improvements to qpAdm protocols: 1) temporal stratification of targets and proxy sources in the case of admixture-graph-shaped histories; 2) focused exploration of few models for increasing pre-study odds; 3) dense landscape sampling for increasing power and stringent conditions on estimated admixture fractions for decreasing the false positive rate.

Patterns of population structure and genetic variation within the Saudi Arabian population

The Arabian Peninsula is considered the initial site of historic human migration out of Africa. The modern-day indigenous Arabians are believed to be the descendants who remained from the ancient split of the migrants into Eurasia. Here, we investigated how the population history and cultural practices such as endogamy have shaped the genetic variation of the Saudi Arabians. We genotyped 3,352 individuals and identified twelve genetic sub-clusters that corresponded to the geographical distribution of different tribal regions, differentiated by distinct components of ancestry based on comparisons to modern and ancient DNA references. These sub-clusters also showed variation across ranges of the genome covered in runs of homozygosity, as well as differences in population size changes over time. Using 25,488,981 variants found in whole genome sequencing data (WGS) from 302 individuals, we found that the Saudi tend to show proportionally more deleterious alleles than neutral alleles when compared to Africans/African Americans from gnomAD (e.g. a 13% increase of deleterious alleles annotated by AlphaMissense between 0.5 - 5% frequency in Saudi, compared to 7% decrease of the benign alleles; P < 0.001). Saudi sub-clusters with greater inbreeding and lower effective population sizes showed greater enrichment of deleterious alleles as well. Additionally, we found that approximately 10% of the variants discovered in our WGS data are not observed in gnomAD; these variants are also enriched with deleterious annotations. To accelerate studying the population-enriched deleterious alleles and their health consequences in this population, we made available the allele frequency estimates of 25,488,981 variants discovered in our samples. Taken together, our results suggest that Saudi's population history impacts its pattern of genetic variation with potential consequences to the population health. It further highlights the need to sequence diverse and unique populations so to provide a foundation on which to interpret medical- and pharmaco- genomic findings from these populations.

The cranium from the Octagon in Ephesos

During excavations in 1929, a well-preserved skeleton was discovered in a sarcophagus in the Octagon at Ephesos (Turkey). For the following century, archaeologists have speculated about the identity of this obviously notable person. Repeated claim is that the remains could represent Arsinoë IV, daughter of Ptolemy XII, and younger (half-)sister of Cleopatra VII. To address these questions we undertook state-of-the-art morphological, genetic and dating analyses of the cranium and further analyses of bone samples from a femur and a rib of the skeleton found in the same tomb. We confirm based on genetic analyses from the cranium and the femur that they derive from the same person. 14C-dating of the cranium provides a most likely time range between 205-36 BC. The connection with Arsinoë IV can be excluded because we confirmed that the individual is a male. The cranium represents an 11-14-year-old boy who suffered from significant developmental disturbances. Genetics suggest an ancestry from the Italian peninsula or Sardinia. The fate of the body of Arsinoë IV, who reportedly was killed in 41 BC in Ephesos, remains open. In contrast, investigations regarding the fate and social background of the boy from the Octagon can now proceed free of speculation.

Traces of Bronze Age globalization in East Asia: Insights from a revised phylogeography of the Y-chromosome haplogroup Q1a1a-M120

OBJECTIVE

In this study, we aim to explore the genetic imprint of Bronze Age globalization in East Asia from a phylogeographic perspective by examining the Y-chromosome haplogroup Q1a1a-M120, and to identify key demographic processes involved in the formation of early China and the ancient Huaxia people.

METHODS

Over the past few decades, we have collected the sequences of 347 Y chromosomes from the haplogroup Q1a1a-M120. These sequences were utilized to analyze and reconstruct a highly revised phylogenetic tree with age estimates. And we analyzed the geographical distribution and spatial autocorrelation of nine major sub-branches of Q1a1a-M120. Finally, we observed the expansion of Q1a1a-M120 from the beginning of the Bronze Age in East Asia, along with the continuous dissemination of its sub-lineages among East Asian populations.

RESULTS

We suggest that certain sub-lineages played a significant role in the formation of states and early civilizations in China, as well as in the development of the ancient Huaxia people, who are the direct ancestors of the Han population. Overall, we propose that haplogroup Q-M120 played a role in the introduction of Bronze Age culture to the central region of East Asia. Therefore, it is haplogroup Q-M120, rather than the Western Eurasian paternal lineage, that expanded and contributed to the gene pool of the East Asian population.

CONCLUSION

In summary, the globalization of the Bronze Age led to large-scale population replacement and admixture across various regions of Eurasia; our findings highlight the unique demographic processes that occurred in East Asia during this period.

Coancestry superposed on admixed populations yields measures of relatedness at individual-level resolution

The admixture model is widely applied to estimate and interpret population structure among individuals. Here we consider a "standard admixture" model that assumes the admixed populations are unrelated and also a generalized model, where the admixed populations themselves are related via coancestry (or covariance) of allele frequencies. The generalized model yields a potentially more realistic and substantially more flexible model that we call "super admixture". This super admixture model provides a one-to-one mapping in terms of probability moments with the population-level kinship model, the latter of which is a general model of genome-wide relatedness and structure based on identity-by-descent. We introduce a method to estimate the super admixture model that is based on method of moments, does not rely on likelihoods, is computationally efficient, and scales to massive sample sizes. We apply the method to several human data sets and show that the admixed populations are indeed substantially related, implying the proposed method captures a new and important component of evolutionary history and structure in the admixture model. We show that the fitted super admixture model estimates relatedness between all pairs of individuals at a resolution similar to the kinship model. The super admixture model therefore provides a tractable, forward generating probabilistic model of complex structure and relatedness that should be useful in a variety of scenarios.

Neanderthal ancestry through time: Insights from genomes of ancient and present-day humans

Gene flow from Neanderthals has shaped genetic and phenotypic variation in modern humans. We generated a catalog of Neanderthal ancestry segments in more than 300 genomes spanning the past 50,000 years. We examined how Neanderthal ancestry is shared among individuals over time. Our analysis revealed that the vast majority of Neanderthal gene flow is attributable to a single, shared extended period of gene flow that occurred between 50,500 to 43,500 years ago, as evidenced by ancestry correlation, colocalization of Neanderthal segments across individuals, and divergence from the sequenced Neanderthals. Most natural selection-positive and negative-on Neanderthal variants occurred rapidly after the gene flow. Our findings provide new insights into how contact with Neanderthals shaped modern human origins and adaptation.

Multiple-Wave Admixture and Adaptive Evolution of the Pamirian Wakhi People

While whole-genome sequencing has been applied extensively to investigate the genetic diversity of global populations, ethnic minority groups in Pakistan are generally underrepresented. In particular, little is known about the genetic origin and highland adaptation of the Pamirian Wakhi people. According to Chinese historical records, the geographical location and language usage of Wakhi may be closely related to Xinjiang Tajiks. In this study, based on high-coverage (∼30×) whole-genome sequencing of eight Wakhi and 25 Xinjiang Tajik individuals, we performed data analyses together with worldwide populations to gain insights into their genetic composition, demography, and adaptive evolution to the highland environment. The Wakhi derived more than 85% of their ancestry from West Eurasian populations (European ∼44.5%, South Asian ∼42.2%) and 10% from East Eurasian populations (Siberian ∼6.0%, East Asian ∼4.3%). Modeling the admixture history of the Wakhi indicated that the early West-East admixture occurred ∼3,875 to 2,250 years ago and that the recent admixture occurred ∼750 to 375 years ago. We identified selection signatures across EGLN3, in particular, a distinctive evolutionary signature was observed, and a certain underlying selected haplotype showed higher frequency (87.5%) in the Wakhi than in nearby Xinjiang Tajiks and other highlanders. Interestingly, we found high-frequency archaic sequences in the Wakhi genome, which overlapped with several genes related to cellular signaling transduction, including MAGI2, previously associated with high-altitude adaptation. Our analysis indicates that the Wakhi are distinct from the Xinjiang Tajiks and Tajikistan Tajiks and sheds light on the Wakhi's ancestral origin and genetic basis of high-altitude adaptation.

Ancient genomics support deep divergence between Eastern and Western Mediterranean Indo-European languages

The Indo-European languages are among the most widely spoken in the world, yet their early diversification remains contentious1-5. It is widely accepted that the spread of this language family across Europe from the 5th millennium BP correlates with the expansion and diversification of steppe-related genetic ancestry from the onset of the Bronze Age6,7. However, multiple steppe-derived populations co-existed in Europe during this period, and it remains unclear how these populations diverged and which provided the demographic channels for the ancestral forms of the Italic, Celtic, Greek, and Armenian languages8,9. To investigate the ancestral histories of Indo-European-speaking groups in Southern Europe, we sequenced genomes from 314 ancient individuals from the Mediterranean and surrounding regions, spanning from 5,200 BP to 2,100 BP, and co-analysed these with published genome data. We additionally conducted strontium isotope analyses on 224 of these individuals. We find a deep east-west divide of steppe ancestry in Southern Europe during the Bronze Age. Specifically, we show that the arrival of steppe ancestry in Spain, France, and Italy was mediated by Bell Beaker (BB) populations of Western Europe, likely contributing to the emergence of the Italic and Celtic languages. In contrast, Armenian and Greek populations acquired steppe ancestry directly from Yamnaya groups of Eastern Europe. These results are consistent with the linguistic Italo-Celtic10,11 and Graeco-Armenian1,12,13 hypotheses accounting for the origins of most Mediterranean Indo-European languages of Classical Antiquity. Our findings thus align with specific linguistic divergence models for the Indo-European language family while contradicting others. This underlines the power of ancient DNA in uncovering prehistoric diversifications of human populations and language communities.

Genetic Polymorphism of Y-Chromosome in Turkmen Population from Turkmenistan

This study investigates the Y-chromosome genetic diversity of the Turkmen population in Turkmenistan, analyzing 23 Y-STR loci for the first time in a sample of 100 individuals. Combined with comparative data from Turkmen populations in Afghanistan, Iran, Iraq, Russia, and Uzbekistan, this analysis offers insights into the genetic structure and relationships among Turkmen populations across regions across Central Asia and the Near East. High haplotype diversity in the Turkmen of Turkmenistan is shaped by founder effects (lineage expansions) from distinct haplogroups, with haplogroups Q and R1a predominating. Subhaplogroups Q1a and Q1b identified in Turkmenistan trace back to ancient Y-chromosome lineages from the Bronze Age. Comparative analyses, including genetic distance (RST), median-joining network, and multidimensional scaling (MDS), highlight the genetic proximity of the Turkmen in Turkmenistan to those in Afghanistan and Iran, while Iraqi Turkmen display unique characteristics, aligning with Near Eastern populations. This study underscores the Central Asian genetic affinity across most Turkmen populations. It demonstrates the value of deep-sequencing Y-chromosome data in tracing the patrilineal history of Central Asia for future studies. These findings contribute to a more comprehensive understanding of Turkmen genetic ancestry and add new data to the ongoing study of Central Asian population genetics.

The genomic portrait of the Picene culture provides new insights into the Italic Iron Age and the legacy of the Roman Empire in Central Italy

BACKGROUND

The Italic Iron Age is characterized by the presence of various ethnic groups partially examined from a genomic perspective. To explore the evolution of Iron Age Italic populations and the genetic impact of Romanization, we focus on the Picenes, one of the most fascinating pre-Roman civilizations, who flourished on the Middle Adriatic side of Central Italy between the 9th and the 3rd century BCE, until the Roman colonization.

RESULTS

More than 50 samples are reported, spanning more than 1000 years of history from the Iron Age to Late Antiquity. Despite cultural diversity, our analysis reveals no major differences between the Picenes and other coeval populations, suggesting a shared genetic history of the Central Italian Iron Age ethnic groups. Nevertheless, a slight genetic differentiation between populations along the Adriatic and Tyrrhenian coasts can be observed, possibly due to different population dynamics in the two sides of Italy and/or genetic contacts across the Adriatic Sea. Additionally, we identify several individuals with ancestries deviating from their general population. Lastly, in our Late Antiquity site, we observe a drastic change in the genetic landscape of the Middle Adriatic region, indicating a relevant influx from the Near East, possibly as a consequence of Romanization.

CONCLUSIONS

Our findings, consistently with archeological hypotheses, suggest genetic interactions across the Adriatic Sea during the Bronze/Iron Age and a high level of individual mobility typical of cosmopolitan societies. Finally, we highlight the role of the Roman Empire in shaping genetic and phenotypic changes that greatly impact the Italian peninsula.

Ancient DNA challenges prevailing interpretations of the Pompeii plaster casts

The eruption of Somma-Vesuvius in 79 CE buried several nearby Roman towns, killing the inhabitants and burying under pumice lapilli and ash deposits a unique set of civil and private buildings, monuments, sculptures, paintings, and mosaics that provide a rich picture of life in the empire. The eruption also preserved the forms of many of the dying as the ash compacted around their bodies. Although the soft tissue decayed, the outlines of the bodies remained and were recovered by excavators centuries later by filling the cavities with plaster. From skeletal material embedded in the casts, we generated genome-wide ancient DNA and strontium isotopic data to characterize the genetic relationships, sex, ancestry, and mobility of five individuals. We show that the individuals' sexes and family relationships do not match traditional interpretations, exemplifying how modern assumptions about gendered behaviors may not be reliable lenses through which to view data from the past. For example, an adult wearing a golden bracelet with a child on their lap-often interpreted as mother and child-is genetically an adult male biologically unrelated to the child. Similarly, a pair of individuals who were thought to have died in an embrace-often interpreted as sisters-included at least one genetic male. All Pompeiians with genome-wide data consistently derive their ancestry largely from recent immigrants from the eastern Mediterranean, as has also been seen in contemporaneous ancient genomes from the city of Rome, underscoring the cosmopolitanism of the Roman Empire in this period.

The maternal genetic history of tribal populations of Chhattisgarh, India

The central region of India boasts a rich tribal heritage and the highest number of tribal populations in the country. Analysing the genetic history of this population can offer valuable insights into various demographic processes that shaped the gene pool of present-day settlers of this region. In this study, we utilize a recently validated Next-generation sequencing (NGS) technique to sequence 24 tribal mitogenomes from the Chhattisgarh population for genetic ancestry and forensic analysis. The identified ancient haplogroups in this population can be traced back to the pre-Last Glacial Maximum (LGM) period. Our Bayesian analysis provides evidence for maternal ancestral expansion following the earliest Out-of-Africa migration, followed by a prolonged steady phase. We identified three basal founding haplogroups, M2, R5, and U2 in the Chhattisgarh region that diversified during the Neolithic period. Indistinct distribution pattern of these haplogroups among tribes and castes suggests that the maternal ancestry of Chhattisgarh population predates any kind of social stratification that exists today in the Indian subcontinent. Furthermore, our analysis suggests that this region remained unaffected by the Last Glacial Maximum. The forensic analysis of the mitogenomes demonstrates a high power of discrimination (0.9256) within the Chhattisgarh population, thus supporting the applicability of mitogenome NGS technology in forensic contexts.

Composite dyadic models for spatio-temporal data

Mechanistic statistical models are commonly used to study the flow of biological processes. For example, in landscape genetics, the aim is to infer spatial mechanisms that govern gene flow in populations. Existing statistical approaches in landscape genetics do not account for temporal dependence in the data and may be computationally prohibitive. We infer mechanisms with a Bayesian hierarchical dyadic model that scales well with large data sets and that accounts for spatial and temporal dependence. We construct a fully connected network comprising spatio-temporal data for the dyadic model and use normalized composite likelihoods to account for the dependence structure in space and time. We develop a dyadic model to account for physical mechanisms commonly found in physical-statistical models and apply our methods to ancient human DNA data to infer the mechanisms that affected human movement in Bronze Age Europe.

Harnessing Generalizable Real-World Ophthalmic Big Data: Descriptive Analysis of the Bodhya Eye Consortium Model for Collaborative Research

BACKGROUND

Eye care organizations and professionals worldwide are increasingly focusing on bridging the gap between population health and medical practice. Recent advances in genomics and anthropology have revealed that most Indian groups trace their ancestry to a blend of 2 genetically distinct populations: Ancestral North Indians, who share genetic affinities with Central Asians, Middle Easterners, Caucasians, and Europeans; and Ancestral South Indians, genetically distinct from groups outside the Indian subcontinent. Studies conducted among North Indian populations can therefore offer insights that are potentially applicable to these diverse global populations, underscoring significant implications for global health.

OBJECTIVE

The Bodhya Eye Consortium is a collaboration among 8 high-volume nonprofit eyecare organizations from across North India. The consortium aims to harness real-world data consistently and with assured quality for collaborative research. This paper outlines the formation of the consortium as a proposed model for controlled collaborative research among the leading eyecare organizations of North India.

METHODS

We detail the creation and effective implementation of a consortium following a structured road map that included planning and assessment, establishing an exploratory task force, defining specialty areas, setting objectives and priorities, and conducting a SWOT (strengths, weaknesses, opportunities, and threats) analysis. Central to this process was a comprehensive data audit aimed at standardizing data collection across all participating organizations.

RESULTS

The consortium currently comprises 9 organizations, each represented in the governance structure by the Governing Council. Scientific standards for published research are established and overseen by the Scientific Committee, while the Conflict Resolution Committee manages any unresolved disputes. The consortium's working groups, organized by various eyecare specialties, collaborate on research projects through virtual interactions. A foundational step in this process was the organizationwide data audit, which revealed that most organizations complied with accurate and standardized data collection practices. Organizations with deficiencies in data completeness developed action plans to address them. Subsequently, the consortium adopted data collection proformas, contributing to the publication of high-quality manuscripts characterized by low dropout rates.

CONCLUSIONS

The collaborative research conducted by the Bodhya Eye Consortium-a group of high-volume eyecare organizations primarily from North India-offers a unique opportunity to contribute to scientific knowledge across various domains of eyecare. By leveraging the established heterogeneity of anthropological and genomic origins within the population, the findings can be generalizable, to some extent, to European, Middle Eastern, and European American populations. This access to potentially invaluable, generalizable data has significant global health implications and opens possibilities for broader collaboration. The model outlined in this descriptive paper can serve as a blueprint for other health care organizations looking to develop similar collaborations for research and knowledge sharing.

Pervasive findings of directional selection realize the promise of ancient DNA to elucidate human adaptation

We present a method for detecting evidence of natural selection in ancient DNA time-series data that leverages an opportunity not utilized in previous scans: testing for a consistent trend in allele frequency change over time. By applying this to 8433 West Eurasians who lived over the past 14000 years and 6510 contemporary people, we find an order of magnitude more genome-wide significant signals than previous studies: 347 independent loci with >99% probability of selection. Previous work showed that classic hard sweeps driving advantageous mutations to fixation have been rare over the broad span of human evolution, but in the last ten millennia, many hundreds of alleles have been affected by strong directional selection. Discoveries include an increase from ~0% to ~20% in 4000 years for the major risk factor for celiac disease at HLA-DQB1; a rise from ~0% to ~8% in 6000 years of blood type B; and fluctuating selection at the TYK2 tuberculosis risk allele rising from ~2% to ~9% from ~5500 to ~3000 years ago before dropping to ~3%. We identify instances of coordinated selection on alleles affecting the same trait, with the polygenic score today predictive of body fat percentage decreasing by around a standard deviation over ten millennia, consistent with the "Thrifty Gene" hypothesis that a genetic predisposition to store energy during food scarcity became disadvantageous after farming. We also identify selection for combinations of alleles that are today associated with lighter skin color, lower risk for schizophrenia and bipolar disease, slower health decline, and increased measures related to cognitive performance (scores on intelligence tests, household income, and years of schooling). These traits are measured in modern industrialized societies, so what phenotypes were adaptive in the past is unclear. We estimate selection coefficients at 9.9 million variants, enabling study of how Darwinian forces couple to allelic effects and shape the genetic architecture of complex traits.

Testing times: disentangling admixture histories in recent and complex demographies using ancient DNA

Our knowledge of human evolutionary history has been greatly advanced by paleogenomics. Since the 2020s, the study of ancient DNA has increasingly focused on reconstructing the recent past. However, the accuracy of paleogenomic methods in resolving questions of historical and archaeological importance amidst the increased demographic complexity and decreased genetic differentiation remains an open question. We evaluated the performance and behavior of two commonly used methods, qpAdm and the f3-statistic, on admixture inference under a diversity of demographic models and data conditions. We performed two complementary simulation approaches-firstly exploring a wide demographic parameter space under four simple demographic models of varying complexities and configurations using branch-length data from two chromosomes-and secondly, we analyzed a model of Eurasian history composed of 59 populations using whole-genome data modified with ancient DNA conditions such as SNP ascertainment, data missingness, and pseudohaploidization. We observe that population differentiation is the primary factor driving qpAdm performance. Notably, while complex gene flow histories influence which models are classified as plausible, they do not reduce overall performance. Under conditions reflective of the historical period, qpAdm most frequently identifies the true model as plausible among a small candidate set of closely related populations. To increase the utility for resolving fine-scaled hypotheses, we provide a heuristic for further distinguishing between candidate models that incorporates qpAdm model P-values and f3-statistics. Finally, we demonstrate a significant performance increase for qpAdm using whole-genome branch-length f2-statistics, highlighting the potential for improved demographic inference that could be achieved with future advancements in f-statistic estimations.

Evaluation of genotype imputation using Glimpse tools on low coverage ancient DNA

Ancient DNA provides a unique frame for directly studying human population genetics in time and space. Still, since most of the ancient genomic data is low coverage, analysis is confronted with a low number of SNPs, genotype uncertainties, and reference-bias. Here, we for the first time benchmark the two distinct versions of Glimpse tools on 120 ancient human genomes from Eurasia including those largely from previously under-evaluated regions and compare the performance of genotype imputation with de facto analysis approaches for low coverage genomic data analysis. We further investigate the impact of two distinct reference panels on imputation accuracy for low coverage genomic data. We compute accuracy statistics and perform PCA and f4-statistics to explore the behaviour of genotype imputation on low coverage data regarding (i)two versions of Glimpse, (ii)two reference panels, (iii)four post-imputation filters and coverages, as well as (iv)data type and geographical origin of the samples on the analyses. Our results reveal that even for 0.1X coverage ancient human genomes, genotype imputation using Glimpse-v2 is suitable. Additionally, using the 1000 Genomes merged with Human Genome Diversity Panel improves the accuracy of imputation for the rare variants with low MAF, which might be important not only for ancient genomics but also for modern human genomic studies based on low coverage data and for haplotype-based analysis. Most importantly, we reveal that genotype imputation of low coverage ancient human genomes reduces the genetic affinity of the samples towards human reference genome. Through solving one of the most challenging biases in data analysis, so-called reference bias, genotype imputation using Glimpse v2 is promising for low coverage ancient human genomic data analysis and for rare-variant-based and haplotype-based analysis.

Repeated plague infections across six generations of Neolithic Farmers

In the period between 5,300 and 4,900 calibrated years before present (cal. BP), populations across large parts of Europe underwent a period of demographic decline1,2. However, the cause of this so-called Neolithic decline is still debated. Some argue for an agricultural crisis resulting in the decline3, others for the spread of an early form of plague4. Here we use population-scale ancient genomics to infer ancestry, social structure and pathogen infection in 108 Scandinavian Neolithic individuals from eight megalithic graves and a stone cist. We find that the Neolithic plague was widespread, detected in at least 17% of the sampled population and across large geographical distances. We demonstrate that the disease spread within the Neolithic community in three distinct infection events within a period of around 120 years. Variant graph-based pan-genomics shows that the Neolithic plague genomes retained ancestral genomic variation present in Yersinia pseudotuberculosis, including virulence factors associated with disease outcomes. In addition, we reconstruct four multigeneration pedigrees, the largest of which consists of 38 individuals spanning six generations, showing a patrilineal social organization. Lastly, we document direct genomic evidence for Neolithic female exogamy in a woman buried in a different megalithic tomb than her brothers. Taken together, our findings provide a detailed reconstruction of plague spread within a large patrilineal kinship group and identify multiple plague infections in a population dated to the beginning of the Neolithic decline.

Nutrition, Other Environmental Influences, and Genetics in the Determination of Human Stature

Linear growth during three distinct stages of life determines attained stature in adulthood: namely, in utero, early postnatal life, and puberty and the adolescent period. Individual host factors, genetics, and the environment, including nutrition, influence attained human stature. Each period of physical growth has its specific biological and environmental considerations. Recent epidemiologic investigations reveal a strong influence of prenatal factors on linear size at birth that in turn influence the postnatal growth trajectory. Although average population height changes have been documented in high-income regions, stature as a complex human trait is not well understood or easily modified. This review summarizes the biology of linear growth and its major drivers, including nutrition from a life-course perspective, the genetics of programmed growth patterns or height, and gene-environment interactions that determine human stature in toto over the life span. Implications for public health interventions and knowledge gaps are discussed.

Ancient genomes reveal over two thousand years of dingo population structure

Dingoes are culturally and ecologically important free-living canids whose ancestors arrived in Australia over 3,000 B.P., likely transported by seafaring people. However, the early history of dingoes in Australia-including the number of founding populations and their routes of introduction-remains uncertain. This uncertainty arises partly from the complex and poorly understood relationship between modern dingoes and New Guinea singing dogs, and suspicions that post-Colonial hybridization has introduced recent domestic dog ancestry into the genomes of many wild dingo populations. In this study, we analyzed genome-wide data from nine ancient dingo specimens ranging in age from 400 to 2,746 y old, predating the introduction of domestic dogs to Australia by European colonists. We uncovered evidence that the continent-wide population structure observed in modern dingo populations had already emerged several thousand years ago. We also detected excess allele sharing between New Guinea singing dogs and ancient dingoes from coastal New South Wales (NSW) compared to ancient dingoes from southern Australia, irrespective of any post-Colonial hybrid ancestry in the genomes of modern individuals. Our results are consistent with several demographic scenarios, including a scenario where the ancestry of dingoes from the east coast of Australia results from at least two waves of migration from source populations with varying affinities to New Guinea singing dogs. We also contribute to the growing body of evidence that modern dingoes derive little genomic ancestry from post-Colonial hybridization with other domestic dog lineages, instead descending primarily from ancient canids introduced to Sahul thousands of years ago.

Distinct positions of genetic and oral histories: Perspectives from India

Over the past decade, genomic data have contributed to several insights on global human population histories. These studies have been met both with interest and critically, particularly by populations with oral histories that are records of their past and often reference their origins. While several studies have reported concordance between oral and genetic histories, there is potential for tension that may stem from genetic histories being prioritized or used to confirm community-based knowledge and ethnography, especially if they differ. To investigate the interplay between oral and genetic histories, we focused on the southwestern region of India and analyzed whole-genome sequence data from 156 individuals identifying as Bunt, Kodava, Nair, and Kapla. We supplemented limited anthropological records on these populations with oral history accounts from community members and historical literature, focusing on references to non-local origins such as the ancient Scythians in the case of Bunt, Kodava, and Nair, members of Alexander the Great's army for the Kodava, and an African-related source for Kapla. We found these populations to be genetically most similar to other Indian populations, with the Kapla more similar to South Indian tribal populations that maximize a genetic ancestry related to Ancient Ancestral South Indians. We did not find evidence of additional genetic sources in the study populations than those known to have contributed to many other present-day South Asian populations. Our results demonstrate that oral and genetic histories may not always provide consistent accounts of population origins and motivate further community-engaged, multi-disciplinary investigations of non-local origin stories in these communities.

Predictive accuracy of genetic variants for eye color in a Kazakh population using the IrisPlex system

OBJECTIVE

This study assesses the accuracy of the IrisPlex system, a genetic eye color prediction tool for forensic analysis, in the Kazakh population. The study compares previously published genotypes of 515 Kazakh individuals from varied geographical and ethnohistorical contexts with phenotypic data on their eye color, introduced for the first time in this research.

RESULTS

The IrisPlex panel's effectiveness in predicting eye color in the Kazakh population was validated. It exhibited slightly lower accuracy than in Western European populations but was higher than in Siberian populations. The sensitivity was notably high for brown-eyed individuals (0.99), but further research is needed for blue and intermediate eye colors. This study establishes IrisPlex as a useful predictive tool in the Kazakh population and provides a basis for future investigations into the genetic basis of phenotypic variations in this diverse population.

Ancestral Origins and Admixture History of Kazakhs

Kazakh people, like many other populations that settled in Central Asia, demonstrate an array of mixed anthropological features of East Eurasian (EEA) and West Eurasian (WEA) populations, indicating a possible scenario of biological admixture between already differentiated EEA and WEA populations. However, their complex biological origin, genomic makeup, and genetic interaction with surrounding populations are not well understood. To decipher their genetic structure and population history, we conducted, to our knowledge, the first whole-genome sequencing study of Kazakhs residing in Xinjiang (KZK). We demonstrated that KZK derived their ancestries from 4 ancestral source populations: East Asian (∼39.7%), West Asian (∼28.6%), Siberian (∼23.6%), and South Asian (∼8.1%). The recognizable interactions of EEA and WEA ancestries in Kazakhs were dated back to the 15th century BCE. Kazakhs were genetically distinctive from the Uyghurs in terms of their overall genomic makeup, although the 2 populations were closely related in genetics, and both showed a substantial admixture of western and eastern peoples. Notably, we identified a considerable sex-biased admixture, with an excess of western males and eastern females contributing to the KZK gene pool. We further identified a set of genes that showed remarkable differentiation in KZK from the surrounding populations, including those associated with skin color (SLC24A5, OCA2), essential hypertension (HLA-DQB1), hypertension (MTHFR, SLC35F3), and neuron development (CNTNAP2). These results advance our understanding of the complex history of contacts between Western and Eastern Eurasians, especially those living or along the old Silk Road.

Characterizing Nonalcoholic Fatty Liver Disease (NAFLD) in Lean Individuals at a Tertiary Care Hospital: A Cross-sectional Study

Background

Fat accumulation in the liver is affecting 38% of the global population. It can also occur in normal-weight individuals, termed lean non-alcoholic fatty liver disease (NAFLD). This study examines Asian and Western body mass index (BMI) criteria, as well as metabolic dysfunction-associated fatty liver disease (MAFLD) and metabolic dysfunction-associated steatotic liver disease (MASLD) diagnostic guidelines, in lean fatty liver cases within a healthcare setting.

Materials and methods

This study was cross-sectional included 111 lean patients diagnosed with NAFLD using either ultrasound or VCTE from January 2023 to March 2024. Anthropometric, laboratory and non-invasive liver fibrosis evaluation parameters were used. The study assessed clinical characteristics and metabolic risk factors of patients with BMI ≤ 23 kg/m2 and BMI between 23 and ≤ 25 kg/m2 using MASLD and MAFLD diagnostic criteria.

Results

The cohort included NAFLD patients with a mean age of 43.3 years (±13.2 years). Of the participants, 33% were diagnosed through ultrasonography, whereas 67% diagnosis were made via Fibro scan. Majority were male 92 (83%), while females were 19 (17%) of the entire group. The lean NAFLD criteria for Asia and the West were satisfied by 43 (39%) persons with a BMI ≤ 23 kg/m2 and 68 (61%) individuals with a BMI between 23 and ≤ 25 kg/m2, respectively. The average body mass index (BMI) was 23.0 ± 1.5 kg/m2. Diabetes was observed in 16%, hypertension 11%, and ischemic heart disease in 2%. Out of the total individuals, 92 satisfied the MASLD-MAFLD criteria, whereas 18 did not qualify the MAFLD criteria for diagnosis and were classed as MASLD-Alone. Elevated triglycerides, insulin resistance (HOMA-IR ≥ 2), and three or more cardiometabolic risk factors (CMRF) were significant in the MASLD-MAFLD group compared to the MASLD-Alone group (p < 0.05). Comparing BMI criteria, no significant differences were found in terms of fibrosis between the Western and Asian lean NAFLD BMI criteria's (p = 0.243).

Conclusion

Lean NAFLD is a major global health concern. Applying non-Asian BMI criteria (BMI ≤ 25 kg/m2) for lean Asians improves early detection and intervention for at-risk individuals. Accurate use of MAFLD and MASLD criteria is essential to prevent confusion in diagnosing lean NAFLD. Further multicenter investigations with larger sample numbers are required to corroborate these results in our community.

How to cite this article

Nazir S, Abbas Z, Gazder DP, et al. Characterizing Nonalcoholic Fatty Liver Disease (NAFLD) in Lean Individuals at a Tertiary Care Hospital: A Cross-sectional Study. Euroasian J Hepato-Gastroenterol 2024;14(2):198-204.

Human Y chromosome haplogroup L1-M22 traces Neolithic expansion in West Asia and supports the Elamite and Dravidian connection

West and South Asian populations profoundly influenced Eurasian genetic and cultural diversity. We investigate the genetic history of the Y chromosome haplogroup L1-M22, which, while prevalent in these regions, lacks in-depth study. Robust Bayesian analyses of 165 high-coverage Y chromosomes favor a West Asian origin for L1-M22 ∼20.6 thousand years ago (kya). Moreover, this haplogroup parallels the genome-wide genetic ancestry of hunter-gatherers from the Iranian Plateau and the Caucasus. We characterized two L1-M22 harboring population groups during the Early Holocene. One expanded with the West Asian Neolithic transition. The other moved to South Asia ∼8-6 kya but showed no expansion. This group likely participated in the spread of Dravidian languages. These South Asian L1-M22 lineages expanded ∼4-3 kya, coinciding with the Steppe ancestry introduction. Our findings advance the current understanding of Eurasian historical dynamics, emphasizing L1-M22's West Asian origin, associated population movements, and possible linguistic impacts.

Ancient genomes revealed the complex human interactions of the ancient western Tibetans

The western Tibetan Plateau is the crossroad between the Tibetan Plateau, Central Asia, and South Asia, and it is a potential human migration pathway connecting these regions. However, the population history of the western Tibetan Plateau remains largely unexplored due to the lack of ancient genomes covering a long-time interval from this area. Here, we reported genome-wide data of 65 individuals dated to 3,500-300 years before present (BP) in the Ngari prefecture. The ancient western Tibetan Plateau populations share the majority of their genetic components with the southern Tibetan Plateau populations and have maintained genetic continuity since 3,500 BP while maintaining interactions with populations within and outside the Tibetan Plateau. Within the Tibetan Plateau, the ancient western Tibetan Plateau populations were influenced by the additional expansion from the south to the southwest plateau before 1,800 BP. Outside the Tibetan Plateau, the western Tibetan Plateau populations interacted with both South and Central Asian populations at least 2,000 years ago, and the South Asian-related genetic influence, despite being very limited, was from the Indus Valley Civilization (IVC) migrants in Central Asia instead of the IVC populations from the Indus Valley. In light of the new genetic data, our study revealed the complex population interconnections across and within the Tibetan Plateau.

Phylogenetic insights into the genetic legacies of Hungarian-speaking communities in the Carpathian Basin

This study focuses on exploring the uniparental genetic lineages of Hungarian-speaking minorities residing in rural villages of Baranja (Croatia) and the Zobor region (Slovakia). We aimed to identify ancestral lineages by examining genetic markers distributed across the entire mitogenome and on the Y-chromosome. This allowed us to discern disparities in regional genetic structures within these communities. By integrating our newly acquired genetic data from a total of 168 participants with pre-existing Eurasian and ancient DNA datasets, our goal was to enrich the understanding of the genetic history trajectories of Carpathian Basin populations. Our findings suggest that while population-based analyses may not be sufficiently robust to detect fine-scale uniparental genetic patterns with the sample sizes at hand, phylogenetic analysis of well-characterized Y-chromosomal Short Tandem Repeat (STR) data and entire mitogenome sequences did uncover multiple lineage ties to far-flung regions and eras. While the predominant portions of both paternal and maternal DNA align with the East-Central European spectrum, rarer subhaplogroups and lineages have unveiled ancient ties to both prehistoric and historic populations spanning Europe and Eastern Eurasia. This research augments the expansive field of phylogenetics, offering critical perspectives on the genetic constitution and heritage of the communities in East-Central Europe.

Evolutionary profiles and complex admixture landscape in East Asia: New insights from modern and ancient Y chromosome variation perspectives

Human Y-chromosomes are characterized by nonrecombination and uniparental inheritance, carrying traces of human history evolution and admixture. Large-scale population-specific genomic sources based on advanced sequencing technologies have revolutionized our understanding of human Y chromosome diversity and its anthropological and forensic applications. Here, we reviewed and meta-analyzed the Y chromosome genetic diversity of modern and ancient people from China and summarized the patterns of founding lineages of spatiotemporally different populations associated with their origin, expansion, and admixture. We emphasized the strong association between our identified founding lineages and language-related human dispersal events correlated with the Sino-Tibetan, Altaic, and southern Chinese multiple-language families related to the Hmong-Mien, Tai-Kadai, Austronesian, and Austro-Asiatic languages. We subsequently summarize the recent advances in translational applications in forensic and anthropological science, including paternal biogeographical ancestry inference (PBGAI), surname investigation, and paternal history reconstruction. Whole-Y sequencing or high-resolution panels with high coverage of terminal Y chromosome lineages are essential for capturing the genomic diversity of ethnolinguistically diverse East Asians. Generally, we emphasized the importance of including more ethnolinguistically diverse, underrepresented modern and spatiotemporally different ancient East Asians in human genetic research for a comprehensive understanding of the paternal genetic landscape of East Asians with a detailed time series and for the reconstruction of a reference database in the PBGAI, even including new technology innovations of Telomere-to-Telomere (T2T) for new genetic variation discovery.

Neandertal ancestry through time: Insights from genomes of ancient and present-day humans

Gene flow from Neandertals has shaped the landscape of genetic and phenotypic variation in modern humans. We identify the location and size of introgressed Neandertal ancestry segments in more than 300 genomes spanning the last 50,000 years. We study how Neandertal ancestry is shared among individuals to infer the time and duration of the Neandertal gene flow. We find the correlation of Neandertal segment locations across individuals and their divergence to sequenced Neandertals, both support a model of single major Neandertal gene flow. Our catalog of introgressed segments through time confirms that most natural selection-positive and negative-on Neandertal ancestry variants occurred immediately after the gene flow, and provides new insights into how the contact with Neandertals shaped human origins and adaptation.

Network of large pedigrees reveals social practices of Avar communities

From AD 567-568, at the onset of the Avar period, populations from the Eurasian Steppe settled in the Carpathian Basin for approximately 250 years1. Extensive sampling for archaeogenomics (424 individuals) and isotopes, combined with archaeological, anthropological and historical contextualization of four Avar-period cemeteries, allowed for a detailed description of the genomic structure of these communities and their kinship and social practices. We present a set of large pedigrees, reconstructed using ancient DNA, spanning nine generations and comprising around 300 individuals. We uncover a strict patrilineal kinship system, in which patrilocality and female exogamy were the norm and multiple reproductive partnering and levirate unions were common. The absence of consanguinity indicates that this society maintained a detailed memory of ancestry over generations. These kinship practices correspond with previous evidence from historical sources and anthropological research on Eurasian Steppe societies2. Network analyses of identity-by-descent DNA connections suggest that social cohesion between communities was maintained via female exogamy. Finally, despite the absence of major ancestry shifts, the level of resolution of our analyses allowed us to detect genetic discontinuity caused by the replacement of a community at one of the sites. This was paralleled with changes in the archaeological record and was probably a result of local political realignment.

A comprehensive review of HVS-I mitochondrial DNA variation of 19 Iranian populations

Iran is located along the Central Asian corridor, a natural artery that has served as a cross-continental route since the first anatomically modern human populations migrated out of Africa. We compiled and reanalyzed the HVS-I (hypervariable segment-I) of 3840 mitochondrial DNA (mtDNA) sequences from 19 Iranian populations and from 26 groups from adjacent countries to give a comprehensive review of the maternal genetic variation and investigate the impact of historical events and cultural factors on the maternal genetic structure of modern Iranians. We conclude that Iranians have a high level of genetic diversity. Thirty-six haplogroups were observed in Iran's populations, and most of them belong to widespread West-Eurasian haplogroups, such as H, HV, J, N, T, and U. In contrast, the predominant haplogroups observed in most of the adjacent countries studied here are H, M, D, R, U, and C haplogroups. Using principal component analysis, clustering, and genetic distance-based calculations, we estimated moderate genetic relationships between Iranian and other Eurasian groups. Further, analyses of molecular variance and comparing geographic and genetic structures indicate that mtDNA HVS-I sequence diversity does not exhibit any sharp geographic structure in the country. Barring a few from some culturally distinct and naturally separated minorities, most Iranian populations have a homogenous maternal genetic structure.

A cross ancestry genetic study of psychiatric disorders from India

Genome-wide association studies across diverse populations may help validate and confirm genetic contributions to risk of disease. We estimated the extent of population stratification as well as the predictive accuracy of polygenic scores (PGS) derived from European samples to a data set from India. We analysed 2685 samples from two data sets, a population neurodevelopmental study (cVEDA) and a hospital-based sample of bipolar affective disorder (BD) and obsessive-compulsive disorder (OCD). Genotyping was conducted using Illumina's Global Screening Array. Population structure was examined with principal component analysis (PCA), uniform manifold approximation and projection (UMAP), support vector machine (SVM) ancestry predictions, and admixture analysis. PGS were calculated from the largest available European discovery GWAS summary statistics for BD, OCD, and externalizing traits using two Bayesian methods that incorporate local linkage disequilibrium structures (PGS-CS-auto) and functional genomic annotations (SBayesRC). Our analyses reveal global and continental PCA overlap with other South Asian populations. Admixture analysis revealed a north-south genetic axis within India (FST 1.6%). The UMAP partially reconstructed the contours of the Indian subcontinent. The Bayesian PGS analyses indicates moderate-to-high predictive power for BD. This was despite the cross-ancestry bias of the discovery GWAS dataset, with the currently available data. However, accuracy for OCD and externalizing traits was much lower. The predictive accuracy was perhaps influenced by the sample size of the discovery GWAS and phenotypic heterogeneity across the syndromes and traits studied. Our study results highlight the accuracy and generalizability of newer PGS models across ancestries. Further research, across diverse populations, would help understand causal mechanisms that contribute to psychiatric syndromes and traits.

Palaeogenomic insights into the origins of early settlers on the island of Cyprus

Archaeological evidence supports sporadic seafaring visits to the Eastern Mediterranean island of Cyprus by Epipaleolithic hunter-gatherers over 12,000 years ago, followed by permanent settlements during the early Neolithic. The geographical origins of these early seafarers have so far remained elusive. By systematically analysing all available genomes from the late Pleistocene to early Holocene Near East (c. 14,000-7000 cal BCE), we provide a comprehensive overview of the genetic landscape of the early Neolithic Fertile Crescent and Anatolia and infer the likely origins of three recently published genomes from Kissonerga-Mylouthkia (Cypriot Late Pre-Pottery Neolithic B, c. 7600-6800 cal BCE). These appear to derive roughly 80% of their ancestry from Aceramic Neolithic Central Anatolians residing in or near the Konya plain, and the remainder from a genetically basal Levantine population. Based on genome-wide weighted ancestry covariance analysis, we infer that this admixture event took place roughly between 14,000 and 10,000 BCE, coinciding with the transition from the Cypriot late Epipaleolithic to the Pre-Pottery Neolithic A (PPNA). Additionally, we identify strong genetic affinities between the examined Cypro-LPPNB individuals and later northwestern Anatolians and the earliest European Neolithic farmers. Our results inform archaeological evidence on prehistoric demographic processes in the Eastern Mediterranean, providing important insights into early seafaring, maritime connections, and insular settlement.