Eurasian Component Research Articles

Клинальная изменчивость генетических детерминант трегалазной недостаточности в популяциях Южной Сибири, Казахстана, Центральной Азии и Монголии

Introduction. Trehalose or mushroom sugar has been increasingly used in the food industry in the past decades. To be absorbed in the human intestine, trehalose needs to be broken down by an enzyme known as trehalase. Today, it is known that the G→A substitution in the rs2276064 locus of the TREH gene results in the reduced activity of this enzyme. The aim of this study was to analyze the frequency of TREH (rs2276064) alleles and genotypes in the populations of South Siberia, Kazakhstan, Central Asia and Mongolia that differ in the contribution of the ancestral East Eurasian (Mongoloid) component to their gene pools. Methods. We genotyped 987 DNA samples collected from the representatives of 17 indigenous populations from Siberia, Kazakhstan and Mongolia. The samples of 311 ethnic Russians comprised a reference dataset. In addition to estimating the frequencies of TREH alleles and genotypes, we analyzed the contribution of the ancestral East Eurasian (Mongoloid) and West Eurasian (European) ADMIXTURE components for the studied populations using an Illumina 750k microarray of SNP markers. Results. The frequency of the A*TREH allele associated with trehalase deficiency increases from west to east (rsp =0.500, p <0.05). TREH is correlated more strongly with the contribution of the ancestral East Eurasian (Mongolian) component than with the geography of the studied populations: rsp =0.613 (p =0.007); with AA*TREH frequency rsp =0.688 (p =0.002). Conclusions. The rs2276064-А TREH allele is more frequent than previously estimated from clinical data. The more substantial is the contribution of the ancestral East Eurasian (Mongoloid) component, the higher is the frequency of the risk A*TREH allele, which rises dramatically to 29-30% in the Kyrgyz, Khakass, Tuvinian and 39% in Khalkha Mongol populations. Together, carriers of the AG and AA*TREH genotypes make up 35% to 65% of the populations of Oriental origin. We hypothesize that the high frequency of genetic trehalase deficiency determinants in the populations of Siberia, Kazakhstan, Central Asia, and Mongolia is associated with their anthropological characteristics and is not purely dependent on geographic factors. @ 2023. This work is licensed under a CC BY 4.0 license

Mitogenome analysis reveals predominantly ancient Yellow River origin of population inhabiting Datong agro-pastoral ecotone along Great Wall.

The Datong Basin was an important arena for population movement and admixture between the Yellow River Valley and Eastern Steppe. In historical materials, the region was often the setting for a tug-of-war between Han farmers and non-Han nomads. The genetic makeup and population history of this Datong population has, however, remained uncertain. In this study, we analysed 289 mitogenomes from Datong individuals. Our primary findings were: (1) population summary statistics analysis revealed a high level of genetic diversity and strong signals of population expansion in the Datong population; (2) inter-population comparisons (PCA and Fst heatmap) exhibited a close clustering between the Datong population and Northern Han, especially northern frontier groups, such as the Inner Mongolia Han, Heilongjiang Han, Liaoning Han and Tianjin Han; (3) phylogeographic analysis of complete mitogenomes revealed the presence of different components in the maternal gene pools of Datong population-the northern East Asian component was dominant (66.44%), whereas the southern East Asians were the second largest component with 31.49%. We also observed a much reduced west Eurasian (2.07%) component; (4) direct comparisons with ancient groups showed closer relationship between Datong and Yellow River farmers than Eastern Steppe nomads. Despite, therefore, centuries of Eastern Steppe nomadic control over the Datong area, Yellow River farmers had a much more significant impact on the Datong population.

The Eurasian Component in the Foreign Policy of the Republic of Belarus, 1991-2021

The article discloses the essence and features of the Eurasian component in the foreign policy of the Republic of Belarus. The scientific novelty of the article lies in revealing the role and place of the Eurasian component in the foreign policy strategy of the Belarusian state at two levels - the Eurasian space as a whole and individual states belonging to this space. Using the tools of neoclassical realism, linking the implementation of the foreign policy process with the state of development of the state, and the theory of foreign policy analysis, the author comes to the conclusion about the increasing importance of the Eurasian component in the foreign policy of Belarus in the second half of the 1990s and the first two decades of the 21st century. According to the author, the course for the development of cooperation between the Republic of Belarus and the Eurasian states was predetermined by its economic interests, although a certain role in its implementation was played by political guidelines of the Belarusian leadership (maintaining stability in the Belarusian state, reinforcing the thesis of the effectiveness of a multi-vector foreign policy, expanding the range of communication in the world arena). A specific feature of the Belarusian Eurasian policy was the absence of a fundamental conceptualization of actions in this direction and the prevalence of situational solutions in building relations with individual Eurasian states. Until the early 2020s, the Eurasian region was considered by the Belarusian authorities and experts mainly in functional and geographical terms, without being perceived as a distinctive civilizational association. At the current stage of development of the Belarusian state, its key partners in Eurasia are Russia, relations with which are being built within the framework of integration associations (the Union State, the EAEU, the CSTO), and China, which is promoting the Belt and Road initiative. However, conceptually, the issue of Belarus geostrategic positioning in Eurasia still needs to be finalized.

Analysis of mitochondrialDNAhaplogroup frequencies in the population of the slab burial mortuary culture of Mongolia (ca. 1100–300 BCE)

AbstractRecent research has shown evidence of ancient admixture from both eastern and western Eurasian genetics in the human populations of Mongolia going back to at least the Eneolithic Afanasievo archaeological culture (ca. 3000 BCE). Eastern mtDNA lineages found in ancient and living Mongolians in the past and present have greatest affinity with Neolithic populations from the Transbaikal region of southern Siberia, suggesting that people from this region were likely the first to colonize northern and eastern Mongolia after the last glacial maximum (ca. 24,500–17,000 BCE), while western Eurasian groups probably migrated to the steppe in association with the earliest forms of pastoralism. While some studies suggest the contribution of these ancient western lineages to the modern populations in Mongolia was minimal, this research demonstrates that western mtDNA lineages were particularly prominent among the burial populations of the Early Iron and Iron Ages in the region. This is most notable among the burial population associated with slab burials and the burial population of their successors, the people associated with the Xiongnu polity (209 BCE–91 CE). Similarities between mtDNA haplogroup frequencies of the slab burial and Xiongnu burial populations also strongly support the proposal that the builders of the slab burials were the principal ancestors of the Xiongnu people.ObjectivesThe objective of this research is to increase understanding of human population change on the Mongolian steppe during the first millennium BCE and how it may be associated with cultural change and the creation of early eastern steppe empires. It examines the mtDNA haplogroup frequencies of the burial population from slab burials in Mongolia and compares it with frequencies from various other populations to determine population affinities.MethodsThis study was primarily based on Sanger sequencing the HV1 of the mtDNA of ancient individuals from Mongolia during the Early Iron Age for haplogroup determination and then comparing mtDNA haplogroup frequencies with previously published data including 110 ancient and modern populations. The 21 samples used in this study were selected based on region, dating, and availability. Pairwise Fsts of mtDNA haplogroup frequencies were calculated using the Arlequin population genetics program.ResultsThe mtDNA hg of 20 of 21 samples are determined and added to previously published data, increasing the total sample to 35 for the particular population of interest. Using this mtDNA gene pool, it is determined that by the Late Bronze Age an east–west mixed population has already been established, which stays relatively stable into the Iron Age (Xiongnu) period, suggesting that the people practicing the slab burial tradition are the most likely biological ancestors of the Xiongnu. It also notes a distinct difference in mtDNA haplogroup frequencies between north‐eastern and central populations in Mongolia during the Iron Age.ConclusionsThere was little change in mtDNA haplogroup frequencies during the first millennium BCE, which contrasts with the clear change in the first millennium CE. MtDNA hg frequencies (matrilines) seemed to be stable at around 28%; however, Y‐ch frequencies have a dramatic shift towards western lineages during the Xiongnu period (300 BCE–200 CE). The mtDNA haplogroup frequencies from the population from the slab burials have close affinity with the Xiongnu population frequencies. This suggests a notable and consistent western Eurasian component in Mongolia during the first millennium BCE, established before the end of the Bronze Age and possibly associated with the introduction of the domestic horse.

Mitogenomics of modern Mongolic-speaking populations.

Here, we present a comprehensive data set of 489 complete mitogenomes (211 of which are new) from four Mongolic-speaking populations (Mongols, Barghuts, Khamnigans, and Buryats) to investigate their matrilineal genetic structure, ancestry and relationship with other ethnic groups. We show that along with very high levels of genetic diversity and lack of genetic differentiation, Mongolic-speaking populations exhibit strong genetic resemblance to East Asian populations of Chinese, Japanese, and Uyghurs. Phylogeographic analysis of complete mitogenomes reveals the presence of different components in the gene pools of modern Mongolic-speaking populations-the main East Eurasian component is represented by mtDNA lineages of East Asian, Siberian and autochthonous (the Baikal region/Mongolian) ancestry, whereas the less pronounced West Eurasian component can be ascribed to Europe and West Asia/Caucasus. We also observed that up to one third of the mtDNA subhaplogroups identified in Mongolic-speaking populations can be considered as Mongolic-specific with the coalescence age of most of them not exceeding 1.7 kya. This coincides well with the population size growth which started around 1.1 kya and is detectable only in the Bayesian Skyline Plot constructed based on Mongolic-specific mitogenomes. Our data suggest that the genetic structure established during the Mongol empire is still retained in present-day Mongolic-speaking populations.

Исследование генетического состава носителей староалейской культуры: постановка проблемы и первые результаты анализа вариабельности мтДНК

Against the intensive studies of the genetic composition of early nomads from the Altai-Sayan mountain system, a number of Scythian populations from the adjacent forest-steppe zone remain unexplored by paleogenetic methods. This article presents the first results of a paleogenetic study of the Staroaleisk culture carriers from the Firsovo-XIV burial ground in the Barnaul Ob region. Analysis of a small series of mitochondrial DNA samples (N = 10) confirmed the participation of populations associated with the autochthonous genetic substrate of the southern regions of Western Siberia in the formation of the genetic composition of the Staroaleisk population (specific composition of the Western Eurasian component of the mtDNA gene pool and the presence of autochthonous Eastern Eurasian A10 haplogroup). We showed the presence of mtDNA (lineages of haplogroups A8 and A11) in the Staroaleisk population, which testifies to its genetic ties with the carriers of the Scythian-Siberian cultures who inhabited the territories to the east of the Upper Ob region – the Altai- Sayan mountain system, Tuva and adjacent regions of Central Asia. Thus, paleogenetic data indicate that the genetic composition of the Sratoaleisk population was formed under the conditions of the genetic interaction between autochthonous populations of the region, whose genetic roots go back to the Bronze Age, and newly migrated groups who were carriers of the cultural traditions of the Scythian-time nomads. Taking into account the informative value of the first genetic results, we can expect a significant detailing of ethnogenetic processes reconstructions with increasing of DNA samples from the Staroaleisk population, analysis of additional genetic markers (Y-chromosome) and obtaining data on the gene pool of other early Iron Age populations from the Upper Ob region and adjacent regions of the South Siberia.

West Asian sources of the Eurasian component in Ethiopians: a reassessment

The presence of genomic signatures of Eurasian origin in contemporary Ethiopians has been reported by several authors and estimated to have arrived in the area from 3000 years ago. Several studies reported plausible source populations for such a signature, using haplotype based methods on modern data or single-site methods on modern or ancient data. These studies did not reach a consensus and suggested an Anatolian or Sardinia-like proxy, broadly Levantine or Neolithic Levantine as possible sources. We demonstrate, however, that the deeply divergent, autochthonous African component which accounts for ~50% of most contemporary Ethiopian genomes, affects the overall allele frequency spectrum to an extent that makes it hard to control for it and, at once, to discern between subtly different, yet important, Eurasian sources (such as Anatolian or Levant Neolithic ones). Here we re-assess pattern of allele sharing between the Eurasian component of Ethiopians (here called “NAF” for Non African) and ancient and modern proxies. Our results unveil a genomic legacy that may connect the Eurasian genetic component of contemporary Ethiopians with Sea People and with population movements that affected the Mediterranean area and the Levant after the fall of the Minoan civilization.

European Roma groups show complex West Eurasian admixture footprints and a common South Asian genetic origin

The Roma population is the largest transnational ethnic minority in Europe, characterized by a linguistic, cultural and historical heterogeneity. Comparative linguistics and genetic studies have placed the origin of European Roma in the Northwest of India. After their migration across Persia, they entered into the Balkan Peninsula, from where they spread into Europe, arriving in the Iberian Peninsula in the 15th century. Their particular demographic history has genetic implications linked to rare and common diseases. However, the South Asian source of the proto-Roma remains still untargeted and the West Eurasian Roma component has not been yet deeply characterized. Here, in order to describe both the South Asian and West Eurasian ancestries, we analyze previously published genome-wide data of 152 European Roma and 34 new Iberian Roma samples at a fine-scale and haplotype-based level, with special focus on the Iberian Roma genetic substructure. Our results suggest that the putative origin of the proto-Roma involves a Punjabi group with low levels of West Eurasian ancestry. In addition, we have identified a complex West Eurasian component (around 65%) in the Roma, as a result of the admixture events occurred with non-proto-Roma populations between 1270–1580. Particularly, we have detected the Balkan genetic footprint in all European Roma, and the Baltic and Iberian components in the Northern and Western Roma groups, respectively. Finally, our results show genetic substructure within the Iberian Roma, with different levels of West Eurasian admixture, as a result of the complex historical events occurred in the Peninsula.

Western Eurasian ancestry in modern Siberians based on mitogenomic data.

BackgroundAlthough the genetic heritage of aboriginal Siberians is mostly of eastern Asian ancestry, a substantial western Eurasian component is observed in the majority of northern Asian populations. Traces of at least two migrations into southern Siberia, one from eastern Europe and the other from western Asia/the Caucasus have been detected previously in mitochondrial gene pools of modern Siberians.ResultsWe report here 166 new complete mitochondrial DNA (mtDNA) sequences that allow us to expand and re-analyze the available data sets of western Eurasian lineages found in northern Asian populations, define the phylogenetic status of Siberian-specific subclades and search for links between mtDNA haplotypes/subclades and events of human migrations. From a survey of 158 western Eurasian mtDNA genomes found in Siberia we estimate that nearly 40% of them most likely have western Asian and another 29% European ancestry. It is striking that 65 of northern Asian mitogenomes, i.e. ~41%, fall into 19 branches and subclades which can be considered as Siberian-specific being found so far only in Siberian populations. From the coalescence analysis it is evident that the sequence divergence of Siberian-specific subclades was relatively small, corresponding to only 0.6-9.5 kya (using the complete mtDNA rate) and 1–6 kya (coding region rate).ConclusionsThe phylogeographic analysis implies that the western Eurasian founders, giving rise to Siberian specific subclades, may trace their ancestry only to the early and mid-Holocene, though some of genetic lineages may trace their ancestry back to the end of Last Glacial Maximum (LGM). We have not found the modern northern Asians to have western Eurasian genetic components of sufficient antiquity to indicate traces of pre-LGM expansions.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-014-0217-9) contains supplementary material, which is available to authorized users.

An investigation of the genetic diversity of the Kerkennah islands and Mahdia (Tunisia) using biparental markers

Background: Kerkennah is one of the main inhabited islands of Tunisia. The origin of the population of Kerkennah has not been established and no well-defined ethnic groups have been identified nor are genetic studies available. Mahdia, a Tunisian coastal city, has a long history dating back to ancient times.Aim: To discover the genetic diversity of the two studied populations and analyse their relationships with other Mediterranean populations.Subject and methods: Seven human-specific Alu insertion polymorphisms were typed in 99 individuals born in Kerkennah and Mahdia.Results: A neighbour-joining tree and MDS multidimensional scaling analysis showed that these Tunisian populations are scattered amongst North African and Europeans populations, indicating their high genetic diversity and mosaic aspect. The important finding of this study was the proximity of Kerkennah to Moroccans. Hence, the actual gene pool of this insular population may descend from the ancestral population known to be of Moroccan origin. Concerning Mahdia, its closeness to Eurasian populations and some Tunisian groups reflected a high Eurasian genetic component for North African populations and confirmed their heterogeneity.Conclusion: The strategic location of the two studied populations and their fortifications have allowed them to play a leading role in the Mediterranean basin.

Autosomal and uniparental portraits of the native populations of Sakha (Yakutia): implications for the peopling of Northeast Eurasia.

BackgroundSakha – an area connecting South and Northeast Siberia – is significant for understanding the history of peopling of Northeast Eurasia and the Americas. Previous studies have shown a genetic contiguity between Siberia and East Asia and the key role of South Siberia in the colonization of Siberia.ResultsWe report the results of a high-resolution phylogenetic analysis of 701 mtDNAs and 318 Y chromosomes from five native populations of Sakha (Yakuts, Evenks, Evens, Yukaghirs and Dolgans) and of the analysis of more than 500,000 autosomal SNPs of 758 individuals from 55 populations, including 40 previously unpublished samples from Siberia. Phylogenetically terminal clades of East Asian mtDNA haplogroups C and D and Y-chromosome haplogroups N1c, N1b and C3, constituting the core of the gene pool of the native populations from Sakha, connect Sakha and South Siberia. Analysis of autosomal SNP data confirms the genetic continuity between Sakha and South Siberia. Maternal lineages D5a2a2, C4a1c, C4a2, C5b1b and the Yakut-specific STR sub-clade of Y-chromosome haplogroup N1c can be linked to a migration of Yakut ancestors, while the paternal lineage C3c was most likely carried to Sakha by the expansion of the Tungusic people. MtDNA haplogroups Z1a1b and Z1a3, present in Yukaghirs, Evens and Dolgans, show traces of different and probably more ancient migration(s). Analysis of both haploid loci and autosomal SNP data revealed only minor genetic components shared between Sakha and the extreme Northeast Siberia. Although the major part of West Eurasian maternal and paternal lineages in Sakha could originate from recent admixture with East Europeans, mtDNA haplogroups H8, H20a and HV1a1a, as well as Y-chromosome haplogroup J, more probably reflect an ancient gene flow from West Eurasia through Central Asia and South Siberia.ConclusionsOur high-resolution phylogenetic dissection of mtDNA and Y-chromosome haplogroups as well as analysis of autosomal SNP data suggests that Sakha was colonized by repeated expansions from South Siberia with minor gene flow from the Lower Amur/Southern Okhotsk region and/or Kamchatka. The minor West Eurasian component in Sakha attests to both recent and ongoing admixture with East Europeans and an ancient gene flow from West Eurasia.

Introducing the Algerian mitochondrial DNA and Y-chromosome profiles into the North African landscape.

North Africa is considered a distinct geographic and ethnic entity within Africa. Although modern humans originated in this Continent, studies of mitochondrial DNA (mtDNA) and Y-chromosome genealogical markers provide evidence that the North African gene pool has been shaped by the back-migration of several Eurasian lineages in Paleolithic and Neolithic times. More recent influences from sub-Saharan Africa and Mediterranean Europe are also evident. The presence of East-West and North-South haplogroup frequency gradients strongly reinforces the genetic complexity of this region. However, this genetic scenario is beset with a notable gap, which is the lack of consistent information for Algeria, the largest country in the Maghreb. To fill this gap, we analyzed a sample of 240 unrelated subjects from a northwest Algeria cosmopolitan population using mtDNA sequences and Y-chromosome biallelic polymorphisms, focusing on the fine dissection of haplogroups E and R, which are the most prevalent in North Africa and Europe respectively. The Eurasian component in Algeria reached 80% for mtDNA and 90% for Y-chromosome. However, within them, the North African genetic component for mtDNA (U6 and M1; 20%) is significantly smaller than the paternal (E-M81 and E-V65; 70%). The unexpected presence of the European-derived Y-chromosome lineages R-M412, R-S116, R-U152 and R-M529 in Algeria and the rest of the Maghreb could be the counterparts of the mtDNA H1, H3 and V subgroups, pointing to direct maritime contacts between the European and North African sides of the western Mediterranean. Female influx of sub-Saharan Africans into Algeria (20%) is also significantly greater than the male (10%). In spite of these sexual asymmetries, the Algerian uniparental profiles faithfully correlate between each other and with the geography.

Mitogenomic Diversity in Tatars from the Volga-Ural Region of Russia

To investigate diversity of mitochondrial gene pool of Tatars inhabiting the territory of the middle Volga River basin, 197 individuals from two populations representing Kazan Tatars and Mishars were subjected for analysis of mitochondrial DNA (mtDNA) control region variation. In addition, 73 mitochondrial genomes of individuals from Mishar population were sequenced completely. It was found that mitochondrial gene pool of the Volga Tatars consists of two parts, but western Eurasian component prevails considerably (84% on average) over eastern Asian one (16%). Eastern Asian mtDNAs detected in Tatars belonged to a heterogeneous set of haplogroups (A, C, D, G, M7, M10, N9a, Y, and Z), although only haplogroups A and D were revealed simultaneously in both populations. Complete mtDNA variation study revealed that the age of western Eurasian haplogroups (such as U4, HV0a, and H) is less than 18,000 years, thus suggesting re-expansion of eastern Europeans soon after the Last Glacial Maximum.

Tracing back ancient south Siberian population history using mitochondrial and Y-chromosome SNPs

Southern Siberian populations have been the subject of intense works attempting to shed light on the peopling of Siberia. From these works, it appeared that south Siberian populations are the reflect of the complex interactions that occurred at different times between Eastern and Western Eurasian people. According to paleoantropological and modern molecular data, European populations predominated in south Siberia during the Bronze age whereas Asian component began to increase from the Iron age. To test this hypothesis we determined the mitochondrial and Y-chromosomal haplotypes and haplogroups of 29 ancient specimens from the Krasnoyarsk area (Southern Central Siberia) dating from the Bronze and Iron ages. The data obtained supported the hypothesis of the prevalence of Western Eurasian component in Southern Central Siberia in the Bronze age. Moreover, they allowed us to propose a geographic origin of the Krasnoyarsk population during this period.

Reconstructing the population history of Puerto Rico by means of mtDNA phylogeographic analysis

The haplogroup identities of 800 mtDNAs randomly and systematically selected to be representative of the population of Puerto Rico were determined by restriction fragment length polymorphism (RFLP), revealing maternal ancestries in this highly mixed population of 61.3% Amerindian, 27.2% sub-Saharan African, and 11.5% West Eurasian. West Eurasian frequencies were low in all 28 municipalities sampled, and displayed no geographic patterns. Thus, a statistically significant negative correlation was observed between the Amerindian and African frequencies of the municipalities. In addition, a statistically highly significant geographic pattern was observed for Amerindian and African mtDNAs. In a scenario in which Amerindian mtDNAs prevailed on either side of longitude 66 degrees 16' West, Amerindian mtDNAs were more frequent west of longitude 66 degrees 16' West than east of it, and the opposite was true for African mtDNAs. Haplogroup A had the highest frequency among Amerindian samples (52.4%), suggesting its predominance among the native Taínos. Principal component analysis showed that the sub-Saharan African fraction had a strong affinity to West Africans. In addition, the magnitudes of the Senegambian and Gulf of Guinea components in Puerto Rico were between those of Cape Verde and São Tomé. Furthermore, the West Eurasian component did not conform to European haplogroup frequencies. HVR-I sequences of haplogroup U samples revealed a strong North African influence among West Eurasian mtDNAs and a new sub-Saharan African clade.

Mitochondrial DNA sequence diversity in a sedentary population from Egypt.

The mitochondrial DNA (mtDNA) diversity of 58 individuals from Upper Egypt, more than half (34 individuals) from Gurna, whose population has an ancient cultural history, were studied by sequencing the control-region and screening diagnostic RFLP markers. This sedentary population presented similarities to the Ethiopian population by the L1 and L2 macrohaplogroup frequency (20.6%), by the West Eurasian component (defined by haplogroups H to K and T to X) and particularly by a high frequency (17.6%) of haplogroup M1. We statistically and phylogenetically analysed and compared the Gurna population with other Egyptian, Near East and sub-Saharan Africa populations; AMOVA and Minimum Spanning Network analysis showed that the Gurna population was not isolated from neighbouring populations. Our results suggest that the Gurna population has conserved the trace of an ancestral genetic structure from an ancestral East African population, characterized by a high M1 haplogroup frequency. The current structure of the Egyptian population may be the result of further influence of neighbouring populations on this ancestral population.

Regional variations in atmospheric deposition and sources of anthropogenic lead in lake sediments across the Canadian Arctic

Stable Pb isotope profiles in dated lake sediment cores were used to gauge the relative amounts and possible sources of anthropogenic Pb deposited from the atmosphere in different regions of the Canadian Arctic. A distinct north-south difference was found. In four High Arctic lakes (i.e., north of 66°N) in this study, recent Pb isotopic shifts or concentration increases attributable to anthropogenic Pb were negligible. The maximum possible contribution from anthropogenic Pb was 0 to 19% of acid-leachable Pb in the 1980s or 1990s. In contrast, two lakes in the Hudson Bay region displayed significantly lower Pb isotope ratios and threefold to fivefold increases of Pb concentrations in modern sediments, corresponding to anthropogenic Pb inputs of at least 72 to 91% of leachable Pb. Eurasian urban and industrial Pb is known to dominate the High Arctic atmosphere. A possible explanation for its negligible influence on northern lake sediments is that atmospheric Pb deposition at northern latitudes is reduced compared with southern regions and is small compared to local geological inputs. 210Pb deposition declines with increasing latitude, apparently because of declining precipitation rates; stable Pb deposition may be similarly affected. Meteorological considerations and variations in the post-1900 Pb isotopic trajectories indicated that the predominant anthropogenic Pb source region in NW Hudson Bay was Eurasia, while in SE Hudson Bay, it was Canada and the United States, with a minor Eurasian component.