Väitekirja elektrooniline versioon ei sisalda publikatsiooneKäesolev on viies Tartu Ülikoolis val... more Väitekirja elektrooniline versioon ei sisalda publikatsiooneKäesolev on viies Tartu Ülikoolis valminud väitekiri Lõuna-Aasia rahvaste geneetilisest ajaloost. Asustatud kaasaegse inimese poolt märksa enne viimase jääaja maksimumi, elab tänapäeval selles regioonis üle 1.8 miljardi inimese – pea veerand inimkonnast. Seega ei ole võimalik süvitsi mõista kaasaegse inimese geneetise varieeruvuse kujunemist, sh eriti väljapool Sahara-alust Aafrikat, omamata detailsemat teadmist Lõuna-Aasia rahvaste geneetikast Väitekiri põhineb neljal ilmunud artiklil. Neist esimeses uurisime Kirde-Indiat asustavaid rahvaid seoses võimaliku pärinevusega Induse oru kultuurist ja järgnenud vedade ajastust. Teine ja kolmas artikkel on pühendatud migratsioonidele, mis tõid Indiasse religioosses mõttes uusi rahvagruppe: parsid Iraanist alates 7. sajandi lõpupoolelt ja juudid, kelle saabumine Indiasse on toimunud mitme lainena. Neljandas artiklis on vaatluse all Nepaalis, kuid ka India põhjapoolsetes osariikides...
Evolutionary trends may underlie some aspects of the risk for common, non-communicable disorders,... more Evolutionary trends may underlie some aspects of the risk for common, non-communicable disorders, including psychiatric disease. We analyzed whole exome sequencing data from 80 unique individuals from India coming from families with two or more individuals with severe mental illness. We used Population Branch Statistics (PBS) to identify variants and genes under positive selection and identified 74 genes as candidates for positive selection. Of these, 20 were previously associated with Schizophrenia, Alzheimer’s disease and cognitive abilities in genome wide association studies. We then checked whether any of these 74 genes were involved in common biological pathways or related to specific cellular or molecular functions. We found that immune related pathways and functions related to innate immunity such as antigen binding were over-represented. We also evaluated for the presence of Neanderthal introgressed segments in these genes and found Neanderthal introgression in a single gene...
The South Asian populations have a mosaic of ancestries likely due to the interactions of long-te... more The South Asian populations have a mosaic of ancestries likely due to the interactions of long-term populations of the landmass and those of East and West Eurasia. Apart from prehistoric dispersals, there are some known population movements to India. In this study, we focussed on the migration of Jewish and Parsi populations on temporal and spatial scales. The existence of Jewish and Parsi communities in India are recorded since ancient times. However, due to the lack of high-resolution genetic data, their origin and affiliation with other Indian and non-Indian populations remains shrouded in legends. Earlier genetic studies on populations of Indian Jews have found evidence for a minor shared ancestry of Indian Jews with Middle Eastern (Jews) populations, whereas for Parsis, the Iranian link was proposed. Recently, in our high-resolution study, we were able to quantify the admixture dynamics of these groups, which has suggested a male-biased admixture. Here, we added the newly available ancient samples and revisited the interplay of genes and cultures. Thus, in this study we reconstructed a broad genetic profile of Indian Jews and Parsis to paint a fine-grained picture of these ethnic groups.
Shifts in the Genetic Landscape of the Western Eurasian Steppe Associated with the Beginning and ... more Shifts in the Genetic Landscape of the Western Eurasian Steppe Associated with the Beginning and End of the Scythian Dominance Highlights d 31 new ancient genomes help compare the Scythians to preand postdating cultures d Scythian dominance brought along an increase of eastern ancestry across the steppe d Results imply some demic diffusion in the spread of the Scythian culture d Genetic makeup agrees with the Gothic source of post-Scythian Chernyakhiv culture
Genetic variation in contemporary South Asian populations follows a northwest to southeast decrea... more Genetic variation in contemporary South Asian populations follows a northwest to southeast decreasing cline of shared West Eurasian ancestry. A growing body of ancient DNA evidence is being used to build increasingly more realistic models of demographic changes in the last few thousand years. Through high-quality modern genomes, these models can be tested for gene and genome level deviations. Using local ancestry deconvolution and masking, we reconstructed population-specific surrogates of the two main ancestral components for more than 500 samples from 25 South Asian populations and showed our approach to be robust via coalescent simulations. Our f3 and f4 statistics–based estimates reveal that the reconstructed haplotypes are good proxies for the source populations that admixed in the area and point to complex interpopulation relationships within the West Eurasian component, compatible with multiple waves of arrival, as opposed to a simpler one wave scenario. Our approach also pro...
The Indus Valley has been the backdrop for several historic and prehistoric population movements ... more The Indus Valley has been the backdrop for several historic and prehistoric population movements between South Asia and West Eurasia. However, the genetic structure of present-day populations from Northwest India is poorly characterized. Here we report new genomewide genotype data for 45 modern individuals from four Northwest Indian populations, including the Ror, whose long-term occupation of the region can be traced back to the early Vedic scriptures. Our results suggest that although the genetic architecture of most Northwest Indian populations fits well on the broader North-South Indian genetic cline, culturally distinct groups such as the Ror stand out by being genetically more akin to populations living west of India; such populations include prehistorical and early historical ancient individuals from the Swat Valley near the Indus Valley. We argue that this affinity is more likely a result of genetic continuity since the Bronze Age migrations from the Steppe Belt than a result of recent admixture. The observed patterns of genetic relationships both with modern and ancient West Eurasians suggest that the Ror can be used as a proxy for a population descended from the Ancestral North Indian (ANI) population. Collectively, our results show that the Indus Valley populations are characterized by considerable genetic heterogeneity that has persisted over thousands of years.
ABSTRACT The estimate of infected people overall may be correct, but it is skeptical as the numbe... more ABSTRACT The estimate of infected people overall may be correct, but it is skeptical as the numbers are contradictory to the world trend of HIV/AIDS and using them, as a reason for complacency is wrong and risky. We should not forget that epidemics affecting around one per cent of the population are often at a point where they can jump from vulnerable groups to the general population. We are seeing more and more cases around us, and few times even these patients don’t want to go to the hospital because of social stigma and discrimination in the society. In one of our study we have found that genetic makeup makes south Indians more susceptible towards HIV/AIDS. There are no studies to show exceptionally high levels of awareness or drastic changes in behavior to explain such a drop. As far as I understand, public awareness alone cannot make that great impact. Even if it is true, we should look back into our method of tracking new infections, to be sure.
Linguistic and genetic studies on Roma populations inhabited in Europe have unequivocally traced ... more Linguistic and genetic studies on Roma populations inhabited in Europe have unequivocally traced these populations to the Indian subcontinent. However, the exact parental population group and time of the out-of-India dispersal have remained disputed. In the absence of archaeological records and with only scanty historical documentation of the Roma, comparative linguistic studies were the first to identify their Indian origin. Recently, molecular studies on the basis of disease-causing mutations and haploid DNA markers (i.e. mtDNA and Y-chromosome) supported the linguistic view. The presence of Indianspecific Y-chromosome haplogroup H1a1a-M82 and mtDNA haplogroups M5a1, M18 and M35b among Roma has corroborated that their South Asian origins and later admixture with Near Eastern and European populations. However, previous studies have left unanswered questions about the exact parental population groups in South Asia. Here we present a detailed phylogeographical study of Y-chromosomal haplogroup H1a1a-M82 in a data set of more than 10,000 global samples to discern a more precise ancestral source of European Romani populations. The phylogeographical patterns and diversity estimates indicate an early origin of this haplogroup in the Indian subcontinent and its further expansion to other regions. Tellingly, the short tandem repeat (STR) based network of H1a1a-M82 lineages displayed the closest connection of Romani haplotypes with the traditional scheduled caste and scheduled tribe population groups of northwestern India.
Linguistic and genetic studies on Roma populations inhabited in Europe have unequivocally traced ... more Linguistic and genetic studies on Roma populations inhabited in Europe have unequivocally traced these populations to the Indian subcontinent. However, the exact parental population group and time of the out-of-India dispersal have remained disputed. In the absence of archaeological records and with only scanty historical documentation of the Roma, comparative linguistic studies were the first to identify their Indian origin. Recently, molecular studies on the basis of disease-causing mutations and haploid DNA markers (i.e. mtDNA and Y-chromosome) supported the linguistic view. The presence of Indianspecific Y-chromosome haplogroup H1a1a-M82 and mtDNA haplogroups M5a1, M18 and M35b among Roma has corroborated that their South Asian origins and later admixture with Near Eastern and European populations. However, previous studies have left unanswered questions about the exact parental population groups in South Asia. Here we present a detailed phylogeographical study of Y-chromosomal haplogroup H1a1a-M82 in a data set of more than 10,000 global samples to discern a more precise ancestral source of European Romani populations. The phylogeographical patterns and diversity estimates indicate an early origin of this haplogroup in the Indian subcontinent and its further expansion to other regions. Tellingly, the short tandem repeat (STR) based network of H1a1a-M82 lineages displayed the closest connection of Romani haplotypes with the traditional scheduled caste and scheduled tribe population groups of northwestern India.
Human settlement and migrations along sides of Bay-of-Bengal have played a vital role in shaping ... more Human settlement and migrations along sides of Bay-of-Bengal have played a vital role in shaping the genetic landscape of Bangladesh, Eastern India and Southeast Asia. Bangladesh and Northeast India form the vital land bridge between the South and Southeast Asia. To reconstruct the population history of this region and to see whether this diverse region geographically acted as a corridor or barrier for human interaction between South Asia and Southeast Asia, we, for the first time analyzed high resolution uniparental (mtDNA and Y chromosome) and biparental autosomal genetic markers among aboriginal Bangladesh tribes currently speaking Tibeto-Burman language. All the three studied populations; Chakma, Marma and Tripura from Bangladesh showed strikingly high homogeneity among themselves and strong affinities to Northeast Indian Tibeto-Burman groups. However, they show substantially higher molecular diversity than Northeast Indian populations. Unlike Austroasiatic (Munda) speakers of India, we observed equal role of both males and females in shaping the Tibeto-Burman expansion in Southern Asia. Moreover, it is noteworthy that in admixture proportion, TB populations of Bangladesh carry substantially higher mainland Indian ancestry component than Northeast Indian Tibeto-Burmans. Largely similar expansion ages of two major paternal haplogroups (O2a and O3a3c), suggested that they arose before the differentiation of any language group and approximately at the same time. Contrary to the scenario proposed for colonization of Northeast India as male founder effect that occurred within the past 4,000 years, we suggest a significantly deep colonization of this region. Overall, our extensive analysis revealed that the population history of South Asian Tibeto-Burman speakers is more complex than it was suggested before.
Human settlement and migrations along sides of Bay-of-Bengal have played a vital role in shaping ... more Human settlement and migrations along sides of Bay-of-Bengal have played a vital role in shaping the genetic landscape of Bangladesh, Eastern India and Southeast Asia. Bangladesh and Northeast India form the vital land bridge between the South and Southeast Asia. To reconstruct the population history of this region and to see whether this diverse region geographically acted as a corridor or barrier for human interaction between South Asia and Southeast Asia, we, for the first time analyzed high resolution uniparental (mtDNA and Y chromosome) and biparental autosomal genetic markers among aboriginal Bangladesh tribes currently speaking Tibeto-Burman language. All the three studied populations; Chakma, Marma and Tripura from Bangladesh showed strikingly high homogeneity among themselves and strong affinities to Northeast Indian Tibeto-Burman groups. However, they show substantially higher molecular diversity than Northeast Indian populations. Unlike Austroasiatic (Munda) speakers of India, we observed equal role of both males and females in shaping the Tibeto-Burman expansion in Southern Asia. Moreover, it is noteworthy that in admixture proportion, TB populations of Bangladesh carry substantially higher mainland Indian ancestry component than Northeast Indian Tibeto-Burmans. Largely similar expansion ages of two major paternal haplogroups (O2a and O3a3c), suggested that they arose before the differentiation of any language group and approximately at the same time. Contrary to the scenario proposed for colonization of Northeast India as male founder effect that occurred within the past 4,000 years, we suggest a significantly deep colonization of this region. Overall, our extensive analysis revealed that the population history of South Asian Tibeto-Burman speakers is more complex than it was suggested before.
Previous Y-chromosome studies have demonstrated that Ashkenazi Levites, members of a paternally i... more Previous Y-chromosome studies have demonstrated that Ashkenazi Levites, members of a paternally inherited Jewish priestly caste, display a distinctive founder event within R1a, the most prevalent Y-chromosome haplogroup in Eastern Europe. Here we report the analysis of 16 whole R1 sequences and show that a set of 19 unique nucleotide substitutions defines the Ashkenazi R1a lineage. While our survey of one of these, M582, in 2,834 R1a samples reveals its absence in 922 Eastern Europeans, we show it is present in all sampled R1a Ashkenazi Levites, as well as in 33.8% of other R1a Ashkenazi Jewish males and 5.9% of 303 R1a Near Eastern males, where it shows considerably higher diversity. Moreover, the M582 lineage also occurs at low frequencies in non-Ashkenazi Jewish populations. In contrast to the previously suggested Eastern European origin for Ashkenazi Levites, the current data are indicative of a geographic source of the Levite founder lineage in the Near East and its likely presence among pre-Diaspora Hebrews.
Previous Y-chromosome studies have demonstrated that Ashkenazi Levites, members of a paternally i... more Previous Y-chromosome studies have demonstrated that Ashkenazi Levites, members of a paternally inherited Jewish priestly caste, display a distinctive founder event within R1a, the most prevalent Y-chromosome haplogroup in Eastern Europe. Here we report the analysis of 16 whole R1 sequences and show that a set of 19 unique nucleotide substitutions defines the Ashkenazi R1a lineage. While our survey of one of these, M582, in 2,834 R1a samples reveals its absence in 922 Eastern Europeans, we show it is present in all sampled R1a Ashkenazi Levites, as well as in 33.8% of other R1a Ashkenazi Jewish males and 5.9% of 303 R1a Near Eastern males, where it shows considerably higher diversity. Moreover, the M582 lineage also occurs at low frequencies in non-Ashkenazi Jewish populations. In contrast to the previously suggested Eastern European origin for Ashkenazi Levites, the current data are indicative of a geographic source of the Levite founder lineage in the Near East and its likely presence among pre-Diaspora Hebrews.
R1a-M420 is one of the most widely spread Y-chromosome haplogroups; however, its substructure wit... more R1a-M420 is one of the most widely spread Y-chromosome haplogroups; however, its substructure within Europe and Asia has remained poorly characterized. Using a panel of 16 244 male subjects from 126 populations sampled across Eurasia, we identified 2923 R1a-M420 Y-chromosomes and analyzed them to a highly granular phylogeographic resolution. Whole Y-chromosome sequence analysis of eight R1a and five R1b individuals suggests a divergence time of B25 000 (95% CI: 21 300-29 000) years ago and a coalescence time within R1a-M417 of B5800 (95% CI: 4800-6800) years. The spatial frequency distributions of R1a sub-haplogroups conclusively indicate two major groups, one found primarily in Europe and the other confined to Central and South Asia. Beyond the major European versus Asian dichotomy, we describe several younger sub-haplogroups. Based on spatial distributions and diversity patterns within the R1a-M420 clade, particularly rare basal branches detected primarily within Iran and eastern Turkey, we conclude that the initial episodes of haplogroup R1a diversification likely occurred in the vicinity of present-day Iran.
BackgroundThe Parsis, one of the smallest religious community in the world, reside in South Asia.... more BackgroundThe Parsis, one of the smallest religious community in the world, reside in South Asia. Previous genetic studies on them, although based on low resolution markers, reported both Iranian and Indian ancestries. To understand the population structure and demographic history of this group in more detail, we analyzed Indian and Pakistani Parsi populations using high-resolution autosomal and uniparental (Y-chromosomal and mitochondrial DNA) markers. Additionally, we also assayed 108 mitochondrial DNA markers among 21 ancient Parsi DNA samples excavated from Sanjan, in present day Gujarat, the place of their original settlement in India.ResultsOur extensive analyses indicated that among present-day populations, the Parsis are genetically closest to Middle Eastern (Iranian and the Caucasus) populations rather than their South Asian neighbors. They also share the highest number of haplotypes with present-day Iranians and we estimate that the admixture of the Parsis with Indian popu...
Surrounded by speakers of Indo-European, Dravidian and Tibeto-Burman languages, around 11 million... more Surrounded by speakers of Indo-European, Dravidian and Tibeto-Burman languages, around 11 million Munda (a branch of Austroasiatic language family) speakers live in the densely populated and genetically diverse South Asia. Their genetic makeup holds components characteristic of South Asians as well as Southeast Asians. The admixture time between these components has been previously estimated on the basis of archaeology, linguistics and uniparental markers. Using genome-wide genotype data of 102 Munda speakers and contextual data from South and Southeast Asia, we retrieved admixture dates between 2000-3800 years ago for different populations of Munda. The best modern proxies for the source populations for the admixture with proportions 0.29/0.71 are Lao people from Laos and Dravidian speakers from Kerala in India. The South Asian population(s), with whom the incoming Southeast Asians intermixed, had a smaller proportion of West Eurasian genetic component than contemporary proxies. Somewhat surprisingly Malaysian Peninsular tribes rather than the geographically closer Austroasiatic languages speakers like Vietnamese and Cambodians show highest sharing of IBD segments with the Munda. In addition, we affirmed that the grouping of the Munda speakers into North and South Munda based on linguistics is in concordance with genome-wide data. Genetically diverse 1-3 South Asia is home to more than a billion people who belong to thousands of distinct socio-culturally or ethnically defined population groups. These groups speak languages of four major language families: Indo-European, Dravidian, Austroasiatic and Trans-Himalayan. Studies based on genome-wide genotype data have shown that the majority of present day populations of the Indian subcontinent derive their genetic ancestry to a large extent from two ancestral populations-ancestral northern and southern Indians-of which the former is genetically close to West Eurasian populations 4-6. In addition to these two components, the Munda speakers of the Austroasiatic family share a minor proportion of their genetic ancestry with Southeast Asian populations 7. Austroasiatic languages are spoken by more than 100 million people in Mainland Southeast Asia (MSEA) and >10 million Austroasiatic speakers 8 of Munda languages live in East and Central parts of India where they are surrounded by Indo-European, Dravidian and Trans-Himalayan languages speakers.
Progressing technologies have led to the development of numerous methods to analyze the emergent ... more Progressing technologies have led to the development of numerous methods to analyze the emergent pool of modern and ancient genetic data that decode the pieces of information hidden inside the genome. This can reveal different facets of the demographic history of not just the human populations but other organisms too. However, these methods are so different in their approaches that they can be applied in numerous ways to comprehend the human past at a deeper level. Considering the diversity and versatility in approaches, here I review a set of broadly used methods that follow a specific approach to identify and explain the admixture events, the singular or multiple mixing between two genetically distinct populations. Particularly, I give an overview of the key methods to explicitly detect and quantify admixture by the measure of relative genetic drift observed in populations analyzing genome-wide data, especially focusing on autosomal SNP markers. These methods may not cover the who...
Recent studies have showed the diverse genetic architecture of the highly consanguineous populati... more Recent studies have showed the diverse genetic architecture of the highly consanguineous populations inhabiting the Arabian Peninsula. Consanguinity coupled with heterogeneity is complex and makes it difficult to understand the bases of population-specific genetic diseases in the region. Therefore, comprehensive genetic characterization of the populations at the finest scale is warranted. Here, we revisit the genetic structure of the Kuwait population by analyzing genome-wide single nucleotide polymorphisms data from 583 Kuwaiti individuals sorted into three subgroups. We envisage a diverse demographic genetic history among the three subgroups based on drift and allelic sharing with modern and ancient individuals. Furthermore, our comprehensive haplotype-based analyses disclose a high genetic heterogeneity among the Kuwaiti populations. We infer the major sources of ancestry within the newly defined groups; one with an obvious predominance of sub-Saharan/Western Africa mostly compri...
Väitekirja elektrooniline versioon ei sisalda publikatsiooneKäesolev on viies Tartu Ülikoolis val... more Väitekirja elektrooniline versioon ei sisalda publikatsiooneKäesolev on viies Tartu Ülikoolis valminud väitekiri Lõuna-Aasia rahvaste geneetilisest ajaloost. Asustatud kaasaegse inimese poolt märksa enne viimase jääaja maksimumi, elab tänapäeval selles regioonis üle 1.8 miljardi inimese – pea veerand inimkonnast. Seega ei ole võimalik süvitsi mõista kaasaegse inimese geneetise varieeruvuse kujunemist, sh eriti väljapool Sahara-alust Aafrikat, omamata detailsemat teadmist Lõuna-Aasia rahvaste geneetikast Väitekiri põhineb neljal ilmunud artiklil. Neist esimeses uurisime Kirde-Indiat asustavaid rahvaid seoses võimaliku pärinevusega Induse oru kultuurist ja järgnenud vedade ajastust. Teine ja kolmas artikkel on pühendatud migratsioonidele, mis tõid Indiasse religioosses mõttes uusi rahvagruppe: parsid Iraanist alates 7. sajandi lõpupoolelt ja juudid, kelle saabumine Indiasse on toimunud mitme lainena. Neljandas artiklis on vaatluse all Nepaalis, kuid ka India põhjapoolsetes osariikides...
Evolutionary trends may underlie some aspects of the risk for common, non-communicable disorders,... more Evolutionary trends may underlie some aspects of the risk for common, non-communicable disorders, including psychiatric disease. We analyzed whole exome sequencing data from 80 unique individuals from India coming from families with two or more individuals with severe mental illness. We used Population Branch Statistics (PBS) to identify variants and genes under positive selection and identified 74 genes as candidates for positive selection. Of these, 20 were previously associated with Schizophrenia, Alzheimer’s disease and cognitive abilities in genome wide association studies. We then checked whether any of these 74 genes were involved in common biological pathways or related to specific cellular or molecular functions. We found that immune related pathways and functions related to innate immunity such as antigen binding were over-represented. We also evaluated for the presence of Neanderthal introgressed segments in these genes and found Neanderthal introgression in a single gene...
The South Asian populations have a mosaic of ancestries likely due to the interactions of long-te... more The South Asian populations have a mosaic of ancestries likely due to the interactions of long-term populations of the landmass and those of East and West Eurasia. Apart from prehistoric dispersals, there are some known population movements to India. In this study, we focussed on the migration of Jewish and Parsi populations on temporal and spatial scales. The existence of Jewish and Parsi communities in India are recorded since ancient times. However, due to the lack of high-resolution genetic data, their origin and affiliation with other Indian and non-Indian populations remains shrouded in legends. Earlier genetic studies on populations of Indian Jews have found evidence for a minor shared ancestry of Indian Jews with Middle Eastern (Jews) populations, whereas for Parsis, the Iranian link was proposed. Recently, in our high-resolution study, we were able to quantify the admixture dynamics of these groups, which has suggested a male-biased admixture. Here, we added the newly available ancient samples and revisited the interplay of genes and cultures. Thus, in this study we reconstructed a broad genetic profile of Indian Jews and Parsis to paint a fine-grained picture of these ethnic groups.
Shifts in the Genetic Landscape of the Western Eurasian Steppe Associated with the Beginning and ... more Shifts in the Genetic Landscape of the Western Eurasian Steppe Associated with the Beginning and End of the Scythian Dominance Highlights d 31 new ancient genomes help compare the Scythians to preand postdating cultures d Scythian dominance brought along an increase of eastern ancestry across the steppe d Results imply some demic diffusion in the spread of the Scythian culture d Genetic makeup agrees with the Gothic source of post-Scythian Chernyakhiv culture
Genetic variation in contemporary South Asian populations follows a northwest to southeast decrea... more Genetic variation in contemporary South Asian populations follows a northwest to southeast decreasing cline of shared West Eurasian ancestry. A growing body of ancient DNA evidence is being used to build increasingly more realistic models of demographic changes in the last few thousand years. Through high-quality modern genomes, these models can be tested for gene and genome level deviations. Using local ancestry deconvolution and masking, we reconstructed population-specific surrogates of the two main ancestral components for more than 500 samples from 25 South Asian populations and showed our approach to be robust via coalescent simulations. Our f3 and f4 statistics–based estimates reveal that the reconstructed haplotypes are good proxies for the source populations that admixed in the area and point to complex interpopulation relationships within the West Eurasian component, compatible with multiple waves of arrival, as opposed to a simpler one wave scenario. Our approach also pro...
The Indus Valley has been the backdrop for several historic and prehistoric population movements ... more The Indus Valley has been the backdrop for several historic and prehistoric population movements between South Asia and West Eurasia. However, the genetic structure of present-day populations from Northwest India is poorly characterized. Here we report new genomewide genotype data for 45 modern individuals from four Northwest Indian populations, including the Ror, whose long-term occupation of the region can be traced back to the early Vedic scriptures. Our results suggest that although the genetic architecture of most Northwest Indian populations fits well on the broader North-South Indian genetic cline, culturally distinct groups such as the Ror stand out by being genetically more akin to populations living west of India; such populations include prehistorical and early historical ancient individuals from the Swat Valley near the Indus Valley. We argue that this affinity is more likely a result of genetic continuity since the Bronze Age migrations from the Steppe Belt than a result of recent admixture. The observed patterns of genetic relationships both with modern and ancient West Eurasians suggest that the Ror can be used as a proxy for a population descended from the Ancestral North Indian (ANI) population. Collectively, our results show that the Indus Valley populations are characterized by considerable genetic heterogeneity that has persisted over thousands of years.
ABSTRACT The estimate of infected people overall may be correct, but it is skeptical as the numbe... more ABSTRACT The estimate of infected people overall may be correct, but it is skeptical as the numbers are contradictory to the world trend of HIV/AIDS and using them, as a reason for complacency is wrong and risky. We should not forget that epidemics affecting around one per cent of the population are often at a point where they can jump from vulnerable groups to the general population. We are seeing more and more cases around us, and few times even these patients don’t want to go to the hospital because of social stigma and discrimination in the society. In one of our study we have found that genetic makeup makes south Indians more susceptible towards HIV/AIDS. There are no studies to show exceptionally high levels of awareness or drastic changes in behavior to explain such a drop. As far as I understand, public awareness alone cannot make that great impact. Even if it is true, we should look back into our method of tracking new infections, to be sure.
Linguistic and genetic studies on Roma populations inhabited in Europe have unequivocally traced ... more Linguistic and genetic studies on Roma populations inhabited in Europe have unequivocally traced these populations to the Indian subcontinent. However, the exact parental population group and time of the out-of-India dispersal have remained disputed. In the absence of archaeological records and with only scanty historical documentation of the Roma, comparative linguistic studies were the first to identify their Indian origin. Recently, molecular studies on the basis of disease-causing mutations and haploid DNA markers (i.e. mtDNA and Y-chromosome) supported the linguistic view. The presence of Indianspecific Y-chromosome haplogroup H1a1a-M82 and mtDNA haplogroups M5a1, M18 and M35b among Roma has corroborated that their South Asian origins and later admixture with Near Eastern and European populations. However, previous studies have left unanswered questions about the exact parental population groups in South Asia. Here we present a detailed phylogeographical study of Y-chromosomal haplogroup H1a1a-M82 in a data set of more than 10,000 global samples to discern a more precise ancestral source of European Romani populations. The phylogeographical patterns and diversity estimates indicate an early origin of this haplogroup in the Indian subcontinent and its further expansion to other regions. Tellingly, the short tandem repeat (STR) based network of H1a1a-M82 lineages displayed the closest connection of Romani haplotypes with the traditional scheduled caste and scheduled tribe population groups of northwestern India.
Linguistic and genetic studies on Roma populations inhabited in Europe have unequivocally traced ... more Linguistic and genetic studies on Roma populations inhabited in Europe have unequivocally traced these populations to the Indian subcontinent. However, the exact parental population group and time of the out-of-India dispersal have remained disputed. In the absence of archaeological records and with only scanty historical documentation of the Roma, comparative linguistic studies were the first to identify their Indian origin. Recently, molecular studies on the basis of disease-causing mutations and haploid DNA markers (i.e. mtDNA and Y-chromosome) supported the linguistic view. The presence of Indianspecific Y-chromosome haplogroup H1a1a-M82 and mtDNA haplogroups M5a1, M18 and M35b among Roma has corroborated that their South Asian origins and later admixture with Near Eastern and European populations. However, previous studies have left unanswered questions about the exact parental population groups in South Asia. Here we present a detailed phylogeographical study of Y-chromosomal haplogroup H1a1a-M82 in a data set of more than 10,000 global samples to discern a more precise ancestral source of European Romani populations. The phylogeographical patterns and diversity estimates indicate an early origin of this haplogroup in the Indian subcontinent and its further expansion to other regions. Tellingly, the short tandem repeat (STR) based network of H1a1a-M82 lineages displayed the closest connection of Romani haplotypes with the traditional scheduled caste and scheduled tribe population groups of northwestern India.
Human settlement and migrations along sides of Bay-of-Bengal have played a vital role in shaping ... more Human settlement and migrations along sides of Bay-of-Bengal have played a vital role in shaping the genetic landscape of Bangladesh, Eastern India and Southeast Asia. Bangladesh and Northeast India form the vital land bridge between the South and Southeast Asia. To reconstruct the population history of this region and to see whether this diverse region geographically acted as a corridor or barrier for human interaction between South Asia and Southeast Asia, we, for the first time analyzed high resolution uniparental (mtDNA and Y chromosome) and biparental autosomal genetic markers among aboriginal Bangladesh tribes currently speaking Tibeto-Burman language. All the three studied populations; Chakma, Marma and Tripura from Bangladesh showed strikingly high homogeneity among themselves and strong affinities to Northeast Indian Tibeto-Burman groups. However, they show substantially higher molecular diversity than Northeast Indian populations. Unlike Austroasiatic (Munda) speakers of India, we observed equal role of both males and females in shaping the Tibeto-Burman expansion in Southern Asia. Moreover, it is noteworthy that in admixture proportion, TB populations of Bangladesh carry substantially higher mainland Indian ancestry component than Northeast Indian Tibeto-Burmans. Largely similar expansion ages of two major paternal haplogroups (O2a and O3a3c), suggested that they arose before the differentiation of any language group and approximately at the same time. Contrary to the scenario proposed for colonization of Northeast India as male founder effect that occurred within the past 4,000 years, we suggest a significantly deep colonization of this region. Overall, our extensive analysis revealed that the population history of South Asian Tibeto-Burman speakers is more complex than it was suggested before.
Human settlement and migrations along sides of Bay-of-Bengal have played a vital role in shaping ... more Human settlement and migrations along sides of Bay-of-Bengal have played a vital role in shaping the genetic landscape of Bangladesh, Eastern India and Southeast Asia. Bangladesh and Northeast India form the vital land bridge between the South and Southeast Asia. To reconstruct the population history of this region and to see whether this diverse region geographically acted as a corridor or barrier for human interaction between South Asia and Southeast Asia, we, for the first time analyzed high resolution uniparental (mtDNA and Y chromosome) and biparental autosomal genetic markers among aboriginal Bangladesh tribes currently speaking Tibeto-Burman language. All the three studied populations; Chakma, Marma and Tripura from Bangladesh showed strikingly high homogeneity among themselves and strong affinities to Northeast Indian Tibeto-Burman groups. However, they show substantially higher molecular diversity than Northeast Indian populations. Unlike Austroasiatic (Munda) speakers of India, we observed equal role of both males and females in shaping the Tibeto-Burman expansion in Southern Asia. Moreover, it is noteworthy that in admixture proportion, TB populations of Bangladesh carry substantially higher mainland Indian ancestry component than Northeast Indian Tibeto-Burmans. Largely similar expansion ages of two major paternal haplogroups (O2a and O3a3c), suggested that they arose before the differentiation of any language group and approximately at the same time. Contrary to the scenario proposed for colonization of Northeast India as male founder effect that occurred within the past 4,000 years, we suggest a significantly deep colonization of this region. Overall, our extensive analysis revealed that the population history of South Asian Tibeto-Burman speakers is more complex than it was suggested before.
Previous Y-chromosome studies have demonstrated that Ashkenazi Levites, members of a paternally i... more Previous Y-chromosome studies have demonstrated that Ashkenazi Levites, members of a paternally inherited Jewish priestly caste, display a distinctive founder event within R1a, the most prevalent Y-chromosome haplogroup in Eastern Europe. Here we report the analysis of 16 whole R1 sequences and show that a set of 19 unique nucleotide substitutions defines the Ashkenazi R1a lineage. While our survey of one of these, M582, in 2,834 R1a samples reveals its absence in 922 Eastern Europeans, we show it is present in all sampled R1a Ashkenazi Levites, as well as in 33.8% of other R1a Ashkenazi Jewish males and 5.9% of 303 R1a Near Eastern males, where it shows considerably higher diversity. Moreover, the M582 lineage also occurs at low frequencies in non-Ashkenazi Jewish populations. In contrast to the previously suggested Eastern European origin for Ashkenazi Levites, the current data are indicative of a geographic source of the Levite founder lineage in the Near East and its likely presence among pre-Diaspora Hebrews.
Previous Y-chromosome studies have demonstrated that Ashkenazi Levites, members of a paternally i... more Previous Y-chromosome studies have demonstrated that Ashkenazi Levites, members of a paternally inherited Jewish priestly caste, display a distinctive founder event within R1a, the most prevalent Y-chromosome haplogroup in Eastern Europe. Here we report the analysis of 16 whole R1 sequences and show that a set of 19 unique nucleotide substitutions defines the Ashkenazi R1a lineage. While our survey of one of these, M582, in 2,834 R1a samples reveals its absence in 922 Eastern Europeans, we show it is present in all sampled R1a Ashkenazi Levites, as well as in 33.8% of other R1a Ashkenazi Jewish males and 5.9% of 303 R1a Near Eastern males, where it shows considerably higher diversity. Moreover, the M582 lineage also occurs at low frequencies in non-Ashkenazi Jewish populations. In contrast to the previously suggested Eastern European origin for Ashkenazi Levites, the current data are indicative of a geographic source of the Levite founder lineage in the Near East and its likely presence among pre-Diaspora Hebrews.
R1a-M420 is one of the most widely spread Y-chromosome haplogroups; however, its substructure wit... more R1a-M420 is one of the most widely spread Y-chromosome haplogroups; however, its substructure within Europe and Asia has remained poorly characterized. Using a panel of 16 244 male subjects from 126 populations sampled across Eurasia, we identified 2923 R1a-M420 Y-chromosomes and analyzed them to a highly granular phylogeographic resolution. Whole Y-chromosome sequence analysis of eight R1a and five R1b individuals suggests a divergence time of B25 000 (95% CI: 21 300-29 000) years ago and a coalescence time within R1a-M417 of B5800 (95% CI: 4800-6800) years. The spatial frequency distributions of R1a sub-haplogroups conclusively indicate two major groups, one found primarily in Europe and the other confined to Central and South Asia. Beyond the major European versus Asian dichotomy, we describe several younger sub-haplogroups. Based on spatial distributions and diversity patterns within the R1a-M420 clade, particularly rare basal branches detected primarily within Iran and eastern Turkey, we conclude that the initial episodes of haplogroup R1a diversification likely occurred in the vicinity of present-day Iran.
BackgroundThe Parsis, one of the smallest religious community in the world, reside in South Asia.... more BackgroundThe Parsis, one of the smallest religious community in the world, reside in South Asia. Previous genetic studies on them, although based on low resolution markers, reported both Iranian and Indian ancestries. To understand the population structure and demographic history of this group in more detail, we analyzed Indian and Pakistani Parsi populations using high-resolution autosomal and uniparental (Y-chromosomal and mitochondrial DNA) markers. Additionally, we also assayed 108 mitochondrial DNA markers among 21 ancient Parsi DNA samples excavated from Sanjan, in present day Gujarat, the place of their original settlement in India.ResultsOur extensive analyses indicated that among present-day populations, the Parsis are genetically closest to Middle Eastern (Iranian and the Caucasus) populations rather than their South Asian neighbors. They also share the highest number of haplotypes with present-day Iranians and we estimate that the admixture of the Parsis with Indian popu...
Surrounded by speakers of Indo-European, Dravidian and Tibeto-Burman languages, around 11 million... more Surrounded by speakers of Indo-European, Dravidian and Tibeto-Burman languages, around 11 million Munda (a branch of Austroasiatic language family) speakers live in the densely populated and genetically diverse South Asia. Their genetic makeup holds components characteristic of South Asians as well as Southeast Asians. The admixture time between these components has been previously estimated on the basis of archaeology, linguistics and uniparental markers. Using genome-wide genotype data of 102 Munda speakers and contextual data from South and Southeast Asia, we retrieved admixture dates between 2000-3800 years ago for different populations of Munda. The best modern proxies for the source populations for the admixture with proportions 0.29/0.71 are Lao people from Laos and Dravidian speakers from Kerala in India. The South Asian population(s), with whom the incoming Southeast Asians intermixed, had a smaller proportion of West Eurasian genetic component than contemporary proxies. Somewhat surprisingly Malaysian Peninsular tribes rather than the geographically closer Austroasiatic languages speakers like Vietnamese and Cambodians show highest sharing of IBD segments with the Munda. In addition, we affirmed that the grouping of the Munda speakers into North and South Munda based on linguistics is in concordance with genome-wide data. Genetically diverse 1-3 South Asia is home to more than a billion people who belong to thousands of distinct socio-culturally or ethnically defined population groups. These groups speak languages of four major language families: Indo-European, Dravidian, Austroasiatic and Trans-Himalayan. Studies based on genome-wide genotype data have shown that the majority of present day populations of the Indian subcontinent derive their genetic ancestry to a large extent from two ancestral populations-ancestral northern and southern Indians-of which the former is genetically close to West Eurasian populations 4-6. In addition to these two components, the Munda speakers of the Austroasiatic family share a minor proportion of their genetic ancestry with Southeast Asian populations 7. Austroasiatic languages are spoken by more than 100 million people in Mainland Southeast Asia (MSEA) and >10 million Austroasiatic speakers 8 of Munda languages live in East and Central parts of India where they are surrounded by Indo-European, Dravidian and Trans-Himalayan languages speakers.
Progressing technologies have led to the development of numerous methods to analyze the emergent ... more Progressing technologies have led to the development of numerous methods to analyze the emergent pool of modern and ancient genetic data that decode the pieces of information hidden inside the genome. This can reveal different facets of the demographic history of not just the human populations but other organisms too. However, these methods are so different in their approaches that they can be applied in numerous ways to comprehend the human past at a deeper level. Considering the diversity and versatility in approaches, here I review a set of broadly used methods that follow a specific approach to identify and explain the admixture events, the singular or multiple mixing between two genetically distinct populations. Particularly, I give an overview of the key methods to explicitly detect and quantify admixture by the measure of relative genetic drift observed in populations analyzing genome-wide data, especially focusing on autosomal SNP markers. These methods may not cover the who...
Recent studies have showed the diverse genetic architecture of the highly consanguineous populati... more Recent studies have showed the diverse genetic architecture of the highly consanguineous populations inhabiting the Arabian Peninsula. Consanguinity coupled with heterogeneity is complex and makes it difficult to understand the bases of population-specific genetic diseases in the region. Therefore, comprehensive genetic characterization of the populations at the finest scale is warranted. Here, we revisit the genetic structure of the Kuwait population by analyzing genome-wide single nucleotide polymorphisms data from 583 Kuwaiti individuals sorted into three subgroups. We envisage a diverse demographic genetic history among the three subgroups based on drift and allelic sharing with modern and ancient individuals. Furthermore, our comprehensive haplotype-based analyses disclose a high genetic heterogeneity among the Kuwaiti populations. We infer the major sources of ancestry within the newly defined groups; one with an obvious predominance of sub-Saharan/Western Africa mostly compri...
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Papers by Ajai Pathak