Genetic Structure of Qiangic Populations Residing in the Western Sichuan Corridor

The Qiangic languages in western Sichuan (WSC) are believed to be the oldest branch of the Sino-Tibetan linguistic family, and therefore, all Sino-Tibetan populations might have originated in WSC. However, very few genetic investigations have been done on Qiangic populations and no genetic evidences for the origin of Sino-Tibetan populations have been provided. By using the informative Y chromosome and mitochondrial DNA (mtDNA) markers, we analyzed the genetic structure of Qiangic populations. Our results revealed a predominantly Northern Asian-specific component in Qiangic populations, especially in maternal lineages. The Qiangic populations are an admixture of the northward migrations of East Asian initial settlers with Y chromosome haplogroup D (D1-M15 and the later originated D3a-P47) in the late Paleolithic age, and the southward Di-Qiang people with dominant haplogroup O3a2c1*-M134 and O3a2c1a-M117 in the Neolithic Age.     

Y-chromosome evidence of southern origin of the East Asian-specific haplogroup O3-M122

The prehistoric peopling of East Asia by modern humans remains controversial with respect to early population migrations. Here, we present a systematic sampling and genetic screening of an East Asian-specific Y-chromosome haplogroup (O3-M122) in 2,332 individuals from diverse East Asian populations. Our results indicate that the O3-M122 lineage is dominant in East Asian populations, with an average frequency of 44.3%. The microsatellite data show that the O3-M122 haplotypes in southern East Asia are more diverse than those in northern East Asia, suggesting a southern origin of the O3-M122 mutation. It was estimated that the early northward migration of the O3-M122 lineages in East Asia occurred approximately 25,000-30,000 years ago, consistent with the fossil records of modern humans in East Asia.     

Y chromosome haplotypes reveal prehistorical migrations to the Himalayas

By using 19 Y chromosome biallelic markers and 3 Y chromosome microsatellite markers, we analyzed the genetic structure of 31 indigenous Sino-Tibetan speaking populations (607 individuals) currently residing in East, Southeast, and South Asia. Our results showed that a T to C mutation at locus M122 is highly prevalent in almost all of the Sino-Tibetan populations, implying a strong genetic affinity among populations in the same language family. Furthermore, the extremely high frequency of H8, a haplotype derived from M122C, in the Sino-Tibetan speaking populations in the Himalayas including Tibet and northeast India indicated a strong bottleneck effect that occurred during a westward and then southward migration of the founding population of Tibeto-Burmans. We, therefore, postulate that the ancient people, who lived in the upper-middle Yellow River basin about 10,000 years ago and developed one of the earliest Neolithic cultures in East Asia, were the ancestors of modern Sino-Tibetan populations.     

Genetic diversity in an Andean population from Peru and regional migration patterns of Amerindians in South America: data from Y chromosome and mitochondrial DNA

The genetic variability of a Quechua-speaking Andean population from Peru was examined on the basis of four Y chromosome markers and restriction sites that define the Amerindian mitochondrial DNA (mtDNA) haplogroups. Forty-nine out of 52 (90.4%) individuals had mtDNA which belonged to one of the four common Amerindian haplogroups, with 54% of the samples belonging to haplogroup B. Among 25 males, 12 had an Amerindian Y chromosome, which exists as four haplotypes defined on the basis of the DYS287, DYS199, DYS392 and DYS19 markers, three of which are shared by Amazonian Amerindians. Thus, there is a clear directionality of marriages, with an estimated genetic admixture with non-Amerindians that is 9 times lower for mtDNA than for Y chromosome DNA. The comparison of mtDNA of Andean Amerindians with that of people from other regions of South America in a total of 1,086 individuals demonstrates a geographical pattern, with a decreasing frequency of A and C haplotypes and increasing frequency of the D haplotype from the north of the Amazon River to the south of the Amazon River, reaching the lowest and the highest frequencies, respectively, in the more southern populations of Chile and Argentina. Conversely, the highest and lowest frequencies of the haplogroup B are found, respectively, in the Andean and the North Amazon regions, and it is absent from some southern populations, suggesting that haplotypes A, C and D, and haplotype B may have been dispersed by two different migratory routes within the continent.     

Using ancient mtDNA to reconstruct the population history of northeastern North America

Mitochondrial DNA (mtDNA) was extracted and analyzed from the skeletal remains of 44 individuals, representing four prehistoric populations, and compared to that from two other prehistoric and several contemporary Native American populations to investigate biological relationships and demographic history in northeastern North America. The mtDNA haplogroup frequencies of ancient human remains from the Morse (Red Ocher tradition, 2,700 BP) and Orendorf (Mississippian tradition, 800 BP) sites from the Central Illinois River Valley, and the Great Western Park (Western Basin tradition, 800 BP) and Glacial Kame (2,900 BP) populations from southwestern Ontario, change over time while maintaining a regional continuity between localities. Haplotype patterns suggest that some ancestors of present day Native Americans in northeastern North America have been in that region for at least 3,000 years but have experienced extensive gene flow throughout time, resulting, at least in part, from a demic expansion of ancestors of modern Algonquian-speaking people. However, genetic drift has also been a significant force, and together with a major population crash after European contact, has altered haplogroup frequencies and caused the loss of many haplotypes.     

Placing Ancient DNA Sequences into Reference Phylogenies

Joint phylogenetic analysis of ancient DNA (aDNA) with modern phylogenies is hampered by low sequence coverage and post-mortem deamination, often resulting in overconservative or incorrect assignment. We provide a new efficient likelihood-based workflow, pathPhynder, that takes advantage of all the polymorphic sites in the target sequence. This effectively evaluates the number of ancestral and derived alleles present on each branch and reports the most likely placement of an ancient sample in the phylogeny and a haplogroup assignment, together with alternatives and supporting evidence. To illustrate the application of pathPhynder, we show improved Y chromosome assignments for published aDNA sequences, using a newly compiled Y variation data set (120,908 markers from 2,014 samples) that significantly enhances Y haplogroup assignment for low coverage samples. We apply the method to all published male aDNA samples from Africa, giving new insights into ancient migrations and the relationships between ancient and modern populations. The same software can be used to place samples with large amounts of missing data into other large non-recombining phylogenies such as the mitochondrial tree.     

Molecular characterization of mitochondrial Amerindian haplogroups and the amelogenin gene in human ancient DNA from three archaeological sites in Lambayeque - Peru

Important pre-Inca civilizations, known by their great political and religious structures, inhabited the northern coast of Peru. Archeological and anthropological studies have shown that people from these villages have hierarchical strata, but the genetic structure has been poorly studied. Here, we aimed to perform a molecular characterization of the Amerindian maternal lineages and the amelogenin gene in skeletons collected from three archeological sites in Lambayeque. Ancient DNA (aDNA) samples were analyzed with conventional PCR to assess the nine-base pair (9 bp) deletion corresponding to mitochondrial haplogroup B and the identification of haplogroups A, C, and D were obtained with PCR-RFLP experiments. The sex was characterized via amplification of the AMEL(X/Y) locus. Haplogroup frequencies were compared with available data from other ancient and modern civilizations from the Peruvian coast and highlands using statistical methods. Our results showed that haplogroup C had the highest frequency, while haplogroup B showed variable diversity in the analyzed populations. The meta-analysis revealed a positive correlation among some coastal villages. We concluded that ancient populations analyzed in our study showed the presence of four Amerindian mitochondrial haplogroups, which is consistent with previous studies.     

Mitochondrial DNA analysis of medieval sheep (Ovis aries) in central Italy reveals the predominance of haplogroup B already in the Middle Ages

We retrieved 34 medieval ovicaprine remains, from three archaeological sites of central Italy dating to about 1000 years old, and analyzed them using mitochondrial DNA. We compared the reconstructed haplogroups with modern sheep samples from Europe and the Middle East and sequences from the literature. In modern sheep, haplogroup HA is present in countries with access to the Mediterranean and close to the domestication center, whereas it is very rare or absent in the rest of Europe. The haplogroup HB was predominant in ancient samples (90%), whereas haplogroup HA was found at 10%. Ancient haplogroups match the present distribution in modern sheep in Italy, indicating that the current proportion of HA/HB was already established in the Middle Ages and is not the result of subsequent events such as selective breeding practices.     

Ancient DNA evidence supports the contribution of Di‐Qiang people to the han Chinese gene pool

Han Chinese is the largest ethnic group in the world. During its development, it gradually integrated with many neighboring populations. To uncover the origin of the Han Chinese, ancient DNA analysis was performed on the remains of 46 humans (～1700 to 1900 years ago) excavated from the Taojiazhai site in Qinghai province, northwest of China, where the Di‐Qiang populations had previously lived. In this study, eight mtDNA haplogroups (A, B, D, F, M*, M10, N9a, and Z) and one Y‐chromosome haplogroup (O3) were identified. All analyses show that the Taojiazhai population presents close genetic affinity to Tibeto‐Burman populations (descendants of Di‐Qiang populations) and Han Chinese, suggesting that the Di‐Qiang populations may have contributed to the Han Chinese genetic pool. Am J Phys Anthropol, 2011. © 2010 Wiley‐Liss, Inc.     

Paleogenetical study of pre‐Columbian samples from Pampa Grande (Salta,Argentina)

Ancient DNA recovered from 21 individuals excavated from burial sites in the Pampa Grande (PG) region (Salta province) of North‐Western Argentina (NWA) was analyzed using various genetic markers (mitochondrial DNA, autosomal STRs, and Y chromosomal STRs). The results were compared to ancient and modern DNA from various populations in the Andean and North Argentinean regions, with the aim of establishing their relationships with PG. The mitochondrial haplogroup frequencies described (11% A, 47% B, and 42% D) presented values comparable to those found for the ancient Andean populations from Peru and San Pedro de Atacama. On the other hand, mitochondrial and Y chromosomal haplotypes were specific to PG, as they did not match any other of the South American populations studied. The described genetic diversity indicates homogeneity in the genetic structure of the ancient Andean populations, which was probably facilitated by the intense exchange network in the Andean zone, in particular among Tiwanaku, San Pedro de Atacama, and NWA. The discovery of haplotypes unique to PG could be due to a loss of genetic diversity caused by recent events affecting the autochthonous populations (establishment of the Inca Empire in the region, colonization by the Europeans). Am J Phys Anthropol 2010. © 2009 Wiley‐Liss, Inc.     

A western Eurasian male is found in 2000‐year‐old elite Xiongnu cemetery in Northeast Mongolia

We analyzed mitochondrial DNA (mtDNA), Y‐chromosome single nucleotide polymorphisms (Y‐SNP), and autosomal short tandem repeats (STR) of three skeletons found in a 2,000‐year‐old Xiongnu elite cemetery in Duurlig Nars of Northeast Mongolia. This study is one of the first reports of the detailed genetic analysis of ancient human remains using the three types of genetic markers. The DNA analyses revealed that one subject was an ancient male skeleton with maternal U2e1 and paternal R1a1 haplogroups. This is the first genetic evidence that a male of distinctive Indo‐European lineages (R1a1) was present in the Xiongnu of Mongolia. This might indicate an Indo‐European migration into Northeast Asia 2,000 years ago. Other specimens are a female with mtDNA haplogroup D4 and a male with Y‐SNP haplogroup C3 and mtDNA haplogroup D4. Those haplogroups are common in Northeast Asia. There was no close kinship among them. The genetic evidence of U2e1 and R1a1 may help to clarify the migration patterns of Indo‐Europeans and ancient East‐West contacts of the Xiongnu Empire. Artifacts in the tombs suggested that the Xiongnu had a system of the social stratification. The West Eurasian male might show the racial tolerance of the Xiongnu Empire and some insight into the Xiongnu society. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc.     

Increased resolution of Y chromosome haplogroup T defines relationships among populations of the Near East, Europe, and Africa

Increasing phylogenetic resolution of the Y chromosome haplogroup tree has led to finer temporal and spatial resolution for studies of human migration. Haplogroup T, initially known as K2 and defined by mutation M70, is found at variable frequencies across West Asia, Africa, and Europe. While several SNPs were recently discovered that extended the length of the branch leading to haplogroup T, only two SNPs are known to mark internal branches of haplogroup T. This low level of phylogenetic resolution has hindered studies of the origin and dispersal of this interesting haplogroup, which is found in Near Eastern non-Jewish populations, Jewish populations from several communities, and in the patrilineage of President Thomas Jefferson. Here we map 10 new SNPs that, together with the previously known SNPs, mark 11 lineages and two large subclades (T1a and T1b) of haplogroup T. We also report a new SNP that links haplogroups T and L within the major framework of Y chromosome evolution. Estimates of the timing of the branching events within haplogroup T, along with a comprehensive geographic survey of the major T subclades, suggest that this haplogroup began to diversify in the Near East -25 kya. Our survey also points to a complex history of dispersal of this rare and informative haplogroup within the Near East and from the Near East to Europe and sub-Saharan Africa. The presence of T1a2 chromosomes in Near Eastern Jewish and non-Jewish populations may reflect early exiles between the ancient lands of Israel and Babylon. The presence of different subclades of T chromosomes in Europe may be explained by both the spread of Neolithic farmers and the later dispersal of Jews from the Near East. Finally, the moderately high frequency (-18%) of T1b* chromosomes in the Lemba of southern Africa supports the hypothesis of a Near Eastern, but not necessarily a Jewish, origin for their paternal line.     

Evidence that a West-East admixed population lived in the Tarim Basin as early as the early Bronze Age

Background

The Tarim Basin, located on the ancient Silk Road, played a very important role in the history of human migration and cultural communications between the West and the East. However, both the exact period at which the relevant events occurred and the origins of the people in the area remain very obscure. In this paper, we present data from the analyses of both Y chromosomal and mitochondrial DNA (mtDNA) derived from human remains excavated from the Xiaohe cemetery, the oldest archeological site with human remains discovered in the Tarim Basin thus far.

Results

Mitochondrial DNA analysis showed that the Xiaohe people carried both the East Eurasian haplogroup (C) and the West Eurasian haplogroups (H and K), whereas Y chromosomal DNA analysis revealed only the West Eurasian haplogroup R1a1a in the male individuals.

Conclusion

Our results demonstrated that the Xiaohe people were an admixture from populations originating from both the West and the East, implying that the Tarim Basin had been occupied by an admixed population since the early Bronze Age. To our knowledge, this is the earliest genetic evidence of an admixed population settled in the Tarim Basin.     

The Peopling of Korea Revealed by Analyses of Mitochondrial DNA and Y-Chromosomal Markers

Background

The Koreans are generally considered a northeast Asian group because of their geographical location. However, recent findings from Y chromosome studies showed that the Korean population contains lineages from both southern and northern parts of East Asia. To understand the genetic history and relationships of Korea more fully, additional data and analyses are necessary.

Methodology and Results

We analyzed mitochondrial DNA (mtDNA) sequence variation in the hypervariable segments I and II (HVS-I and HVS-II) and haplogroup-specific mutations in coding regions in 445 individuals from seven east Asian populations (Korean, Korean-Chinese, Mongolian, Manchurian, Han (Beijing), Vietnamese and Thais). In addition, published mtDNA haplogroup data (N = 3307), mtDNA HVS-I sequences (N = 2313), Y chromosome haplogroup data (N = 1697) and Y chromosome STR data (N = 2713) were analyzed to elucidate the genetic structure of East Asian populations. All the mtDNA profiles studied here were classified into subsets of haplogroups common in East Asia, with just two exceptions. In general, the Korean mtDNA profiles revealed similarities to other northeastern Asian populations through analysis of individual haplogroup distributions, genetic distances between populations or an analysis of molecular variance, although a minor southern contribution was also suggested. Reanalysis of Y-chromosomal data confirmed both the overall similarity to other northeastern populations, and also a larger paternal contribution from southeastern populations.

Conclusion

The present work provides evidence that peopling of Korea can be seen as a complex process, interpreted as an early northern Asian settlement with at least one subsequent male-biased southern-to-northern migration, possibly associated with the spread of rice agriculture.     

Y-chromosome analysis in Egypt suggests a genetic regional continuity in Northeastern Africa

The geographic location of Egypt, at the interface between North Africa, the Middle East, and southern Europe, prompted us to investigate the genetic diversity of this population and its relationship with neighboring populations. To assess the extent to which the modern Egyptian population reflects this intermediate geographic position, ten Unique Event Polymorphisms (UEPs), mapping to the nonrecombining portion of the Y chromosome, have been typed in 164 Y chromosomes from three North African populations. The analysis of these binary markers, which define 11 Y-chromosome lineages, were used to determine the haplogroup frequencies in Egyptians, Moroccan Arabs, and Moroccan Berbers and thereby define the Y-chromosome background in these regions. Pairwise comparisons with a set of 15 different populations from neighboring European, North African, and Middle Eastern populations and geographic analysis showed the absence of any significant genetic barrier in the eastern part of the Mediterranean area, suggesting that genetic variation and gene flow in this area follow the "isolation-by-distance" model. These results are in sharp contrast with the observation of a strong north-south genetic barrier in the western Mediterranean basin, defined by the Gibraltar Strait. Thus, the Y-chromosome gene pool in the modern Egyptian population reflects a mixture of European, Middle Eastern, and African characteristics, highlighting the importance of ancient and recent migration waves, followed by gene flow, in the region.     

Northern gene flow into southeastern East Asians inferred from genome-wide array genotyping

The population history of Southeast (SE) China remains poorly understood due to the sparse sampling of present-day populations and limited modeling with ancient genomic data. We report genome-wide genotyping data from 207 present-day Han Chinese and Hmong-Mien (HM)-speaking She people from Fujian and Taiwan Island, SE China. We coanalyzed 66 Early Neolithic to Iron Age ancient Fujian and Taiwan Island individuals obtained from previously published works to explore the genetic continuity and admixture based on patterns of genetic variations of the high-resolution time transect. We found the genetic differentiation between northern and southern East Asians was defined by a north–south East Asian genetic cline and our studied southern East Asians were clustered in the southern end of this cline. The southeastern coastal modern East Asians are genetically similar to other southern indigenous groups as well as geographically close to Neolithic-to-Iron Age populations, but they also shared excess alleles with post-Neolithic Yellow River ancients, which suggested a southward gene flow on the modern southern coastal gene pool. In addition, we identified one new HM genetic cline in East Asia with the coastal Fujian HM-speaking She localizing at the intersection between HM and Han clines. She people show stronger genetic affinity with southern East Asian indigenous populations, with the main ancestry deriving from groups related to southeastern ancient indigenous rice farmers. The southeastern Han Chinese could be modeled with the primary ancestry deriving from the group related to the Yellow River Basin millet farmers and the remaining from groups related to rice farmers, which was consistent with the northern China origin of modern southeastern Han Chinese and in line with the historically and archaeologically attested southward migrations of Han people and their ancestors. Our estimated north–south admixture time ranges based on the decay of the linkage disequilibrium spanned from the Bronze Age to historic periods, suggesting the recent large-scale population migrations and subsequent admixture participated in the formation of modern Han in SE Asia.     

Mitochondrial DNA from El Mirador Cave (Atapuerca,Spain) Reveals the Heterogeneity of Chalcolithic Populations

Previous mitochondrial DNA analyses on ancient European remains have suggested that the current distribution of haplogroup H was modeled by the expansion of the Bell Beaker culture (ca 4,500–4,050 years BP) out of Iberia during the Chalcolithic period. However, little is known on the genetic composition of contemporaneous Iberian populations that do not carry the archaeological tool kit defining this culture. Here we have retrieved mitochondrial DNA (mtDNA) sequences from 19 individuals from a Chalcolithic sample from El Mirador cave in Spain, dated to 4,760–4,200 years BP and we have analyzed the haplogroup composition in the context of modern and ancient populations. Regarding extant African, Asian and European populations, El Mirador shows affinities with Near Eastern groups. In different analyses with other ancient samples, El Mirador clusters with Middle and Late Neolithic populations from Germany, belonging to the Rössen, the Salzmünde and the Baalberge archaeological cultures but not with contemporaneous Bell Beakers. Our analyses support the existence of a common genetic signal between Western and Central Europe during the Middle and Late Neolithic and points to a heterogeneous genetic landscape among Chalcolithic groups.     

Ancient DNA Analysis of 8000 B.C. Near Eastern Farmers Supports an Early Neolithic Pioneer Maritime Colonization of Mainland Europe through Cyprus and the Aegean Islands

The genetic impact associated to the Neolithic spread in Europe has been widely debated over the last 20 years. Within this context, ancient DNA studies have provided a more reliable picture by directly analyzing the protagonist populations at different regions in Europe. However, the lack of available data from the original Near Eastern farmers has limited the achieved conclusions, preventing the formulation of continental models of Neolithic expansion. Here we address this issue by presenting mitochondrial DNA data of the original Near-Eastern Neolithic communities with the aim of providing the adequate background for the interpretation of Neolithic genetic data from European samples. Sixty-three skeletons from the Pre Pottery Neolithic B (PPNB) sites of Tell Halula, Tell Ramad and Dja''de El Mughara dating between 8,700–6,600 cal. B.C. were analyzed, and 15 validated mitochondrial DNA profiles were recovered. In order to estimate the demographic contribution of the first farmers to both Central European and Western Mediterranean Neolithic cultures, haplotype and haplogroup diversities in the PPNB sample were compared using phylogeographic and population genetic analyses to available ancient DNA data from human remains belonging to the Linearbandkeramik-Alföldi Vonaldiszes Kerámia and Cardial/Epicardial cultures. We also searched for possible signatures of the original Neolithic expansion over the modern Near Eastern and South European genetic pools, and tried to infer possible routes of expansion by comparing the obtained results to a database of 60 modern populations from both regions. Comparisons performed among the 3 ancient datasets allowed us to identify K and N-derived mitochondrial DNA haplogroups as potential markers of the Neolithic expansion, whose genetic signature would have reached both the Iberian coasts and the Central European plain. Moreover, the observed genetic affinities between the PPNB samples and the modern populations of Cyprus and Crete seem to suggest that the Neolithic was first introduced into Europe through pioneer seafaring colonization.     

Evidence of authentic DNA from Danish Viking Age skeletons untouched by humans for 1,000 years

Background

Given the relative abundance of modern human DNA and the inherent impossibility for incontestable proof of authenticity, results obtained on ancient human DNA have often been questioned. The widely accepted rules regarding ancient DNA work mainly affect laboratory procedures, however, pre-laboratory contamination occurring during excavation and archaeological-/anthropological handling of human remains as well as rapid degradation of authentic DNA after excavation are major obstacles.

Methodology/Principal Findings

We avoided some of these obstacles by analyzing DNA from ten Viking Age subjects that at the time of sampling were untouched by humans for 1,000 years. We removed teeth from the subjects prior to handling by archaeologists and anthropologists using protective equipment. An additional tooth was removed after standard archaeological and anthropological handling. All pre-PCR work was carried out in a “clean- laboratory” dedicated solely to ancient DNA work. Mitochondrial DNA was extracted and overlapping fragments spanning the HVR-1 region as well as diagnostic sites in the coding region were PCR amplified, cloned and sequenced. Consistent results were obtained with the “unhandled” teeth and there was no indication of contamination, while the latter was the case with half of the “handled” teeth. The results allowed the unequivocal assignment of a specific haplotype to each of the subjects, all haplotypes being compatible in their character states with a phylogenetic tree drawn from present day European populations. Several of the haplotypes are either infrequent or have not been observed in modern Scandinavians. The observation of haplogroup I in the present study (<2% in modern Scandinavians) supports our previous findings of a pronounced frequency of this haplogroup in Viking and Iron Age Danes.

Conclusion

The present work provides further evidence that retrieval of ancient human DNA is a possible task provided adequate precautions are taken and well-considered sampling is applied.     

Population affinities of Neolithic Siberians: a snapshot from prehistoric Lake Baikal

Archaeological evidence supports the inhabitation of the Lake Baikal region since the Paleolithic. Both metric and nonmetric osteological studies suggest that Neolithic Cis-Baikal populations are the ancestors of contemporary inhabitants of the region. To date, ancient DNA data have not been used to corroborate this biological continuity hypothesis. This study presents a temporal snapshot of the Cis-Baikal Neolithic by examining mtDNA diversity in two cemetery populations situated on the Angara River downstream of Lake Baikal. The 800 years separating the use of the two cemeteries is thought to represent a biocultural hiatus in the Cis-Baikal region, one that ended when a new group migrated into the area. To assess the likelihood that genetic continuity exists between these two Neolithic groups, we examined both mtDNA coding region and hypervariable region I (HVI) polymorphisms from skeletal remains excavated from both cemeteries (Lokomotiv and Ust'-Ida). The mtDNA haplogroup distributions of the two cemetery populations differ significantly, suggesting that they were biologically distinct groups. When the biological distance between these Neolithic groups is compared with modern Siberian and other East Eurasian groups, the posthiatus group (Serovo-Glazkovo) generally aligns with contemporary Siberians, while the prehiatus (Kitoi) individuals are significantly different from all but modern Kets and Shorians living in the Yenisey and Ob River basins to the west of Lake Baikal. These results suggest that the Lake Baikal region experienced a significant depopulation event during the sixth millennium BP, and was reoccupied by a new immigrant population some 800 years later.