Peopling of South Asia: investigating the caste-tribe continuum in India

In recent years, mtDNA and Y chromosome studies involving human populations from South Asia and the rest of the world have revealed new insights about the peopling of the world by anatomically modern humans during the late Pleistocene, some 40,000-60,000 years ago, over the southern coastal route from Africa. Molecular studies and archaeological record are both largely consistent with autochthonous differentiation of the genetic structure of the caste and tribal populations in South Asia. High level of endogamy created by numerous social boundaries within and between castes and tribes, along with the influence of several evolutionary forces such as genetic drift, fragmentation and long-term isolation, has kept the Indian populations diverse and distant from each other as well as from other continental populations. This review attempts to summarize recent genetic studies on Indian caste and tribal populations with the focus on the information embedded in the socially defined structure of Indian populations.     

Deep common ancestry of indian and western-Eurasian mitochondrial DNA lineages

About a fifth of the human gene pool belongs largely either to Indo-European or Dravidic speaking people inhabiting the Indian peninsula. The 'Caucasoid share' in their gene pool is thought to be related predominantly to the Indo-European speakers. A commonly held hypothesis, albeit not the only one, suggests a massive Indo-Aryan invasion to India some 4,000 years ago [1]. Recent limited analysis of maternally inherited mitochondrial DNA (mtDNA) of Indian populations has been interpreted as supporting this concept [2] [3]. Here, this interpretation is questioned. We found an extensive deep late Pleistocene genetic link between contemporary Europeans and Indians, provided by the mtDNA haplogroup U, which encompasses roughly a fifth of mtDNA lineages of both populations. Our estimate for this split is close to the suggested time for the peopling of Asia and the first expansion of anatomically modern humans in Eurasia [4] [5] [6] [7] [8] and likely pre-dates their spread to Europe. Only a small fraction of the 'Caucasoid-specific' mtDNA lineages found in Indian populations can be ascribed to a relatively recent admixture.     

Genetic diversity and evidence for population admixture in Batak Negritos from Palawan

Anthropologists have long been fascinated by the isolated hunter-gatherer populations in Southeast Asia (SEA) collectively known as "Negritos." However, the origins and affinities of these groups remain unresolved. Negritos are characterized by their short stature, dark skin color, and wiry hair, and they inhabit the Philippines, Malay Peninsula, and the Andaman Islands. Among Philippine Negritos, the Batak are of particular interest in understanding population interactions in the region due to their location on Palawan Island, which likely formed a corridor by which human migrations entered the rest of the Philippine archipelago from Island SEA. Here, we extend current understanding of the distribution of genetic diversity in Negritos by presenting the first analysis of mitochondrial DNA and Y-chromosome diversity among the Batak. We show that the Batak are genetically distinct from Negritos of the Andaman Islands and Malay Peninsula and instead bear most resemblance to geographically proximate Philippine Negritos and to non-Negrito populations from the Philippines and Island SEA. An extensive degree of recent admixture between the Batak and their neighbors is indicated by the high frequency of recently coalescing haplogroups in the Batak that are found throughout Island SEA. The comparison of results from these two loci further lends support to the hypothesis that male-biased admixture has, in particular, been a prominent feature of the interactions between the Batak and surrounding non-Negrito populations.     

Mitochondrial DNA evidence supports northeast Indian origin of the aboriginal Andamanese in the Late Paleolithic

In view of the geographically closest location to Andaman archipelago,Myanmar was suggested to be the origin place of aboriginal Andamanese.However,for lacking any genetic information from this region,which has prevented to resolve the dispute on whether the aboriginal Andamanese were originated from mainland India or Myanmar.To solve this question and better understand the origin of the aboriginal Andamanese,we screened for haplogroups M31(from which Andaman-specific lineage M31a1 branched off)and M32 among 846mitochondrial DNAs(mtDNAs)sampled across Myanmar.As a result,two Myanmar individuals belonging to haplogroup M31 were identified,and completely sequencing the entire mtDNA genomes of both samples testified that the two M31 individuals observed in Myanmar were probably attributed to the recent gene flow from northeast India populations.Since no root lineages of haplogroup M31 or M32 were observed in Myanmar,it is unlikely that Myanmar may serve as the source place of the aboriginal Andamanese.To get further insight into the origin of this unique population,the detailed phylogenetic and phylogeographic analyses were performed by including additional 7 new entire mtDNA genomes and 113 M31 mtDNAs pinpointed from South Asian populations,and the results suggested that Andaman-specific M31a1 could in fact trace its origin to northeast India.Time estimation results further indicated that the Andaman archipelago was likely settled by modern humans from northeast India via the land-bridge which connected the Andaman archipelago and Myanmar around the Last Glacial Maximum(LGM),a scenario in well agreement with the evidence from linguistic and palaeoclimate studies.     

Most of the extant mtDNA boundaries in South and Southwest Asia were likely shaped during the initial settlement of Eurasia by anatomically modern humans

Background

Recent advances in the understanding of the maternal and paternal heritage of south and southwest Asian populations have highlighted their role in the colonization of Eurasia by anatomically modern humans. Further understanding requires a deeper insight into the topology of the branches of the Indian mtDNA phylogenetic tree, which should be contextualized within the phylogeography of the neighboring regional mtDNA variation. Accordingly, we have analyzed mtDNA control and coding region variation in 796 Indian (including both tribal and caste populations from different parts of India) and 436 Iranian mtDNAs. The results were integrated and analyzed together with published data from South, Southeast Asia and West Eurasia.

Results

Four new Indian-specific haplogroup M sub-clades were defined. These, in combination with two previously described haplogroups, encompass approximately one third of the haplogroup M mtDNAs in India. Their phylogeography and spread among different linguistic phyla and social strata was investigated in detail. Furthermore, the analysis of the Iranian mtDNA pool revealed patterns of limited reciprocal gene flow between Iran and the Indian sub-continent and allowed the identification of different assemblies of shared mtDNA sub-clades.

Conclusions

Since the initial peopling of South and West Asia by anatomically modern humans, when this region may well have provided the initial settlers who colonized much of the rest of Eurasia, the gene flow in and out of India of the maternally transmitted mtDNA has been surprisingly limited. Specifically, our analysis of the mtDNA haplogroups, which are shared between Indian and Iranian populations and exhibit coalescence ages corresponding to around the early Upper Paleolithic, indicates that they are present in India largely as Indian-specific sub-lineages. In contrast, other ancient Indian-specific variants of M and R are very rare outside the sub-continent.     

The genetic heritage of the earliest settlers persists both in Indian tribal and caste populations

Two tribal groups from southern India--the Chenchus and Koyas--were analyzed for variation in mitochondrial DNA (mtDNA), the Y chromosome, and one autosomal locus and were compared with six caste groups from different parts of India, as well as with western and central Asians. In mtDNA phylogenetic analyses, the Chenchus and Koyas coalesce at Indian-specific branches of haplogroups M and N that cover populations of different social rank from all over the subcontinent. Coalescence times suggest early late Pleistocene settlement of southern Asia and suggest that there has not been total replacement of these settlers by later migrations. H, L, and R2 are the major Indian Y-chromosomal haplogroups that occur both in castes and in tribal populations and are rarely found outside the subcontinent. Haplogroup R1a, previously associated with the putative Indo-Aryan invasion, was found at its highest frequency in Punjab but also at a relatively high frequency (26%) in the Chenchu tribe. This finding, together with the higher R1a-associated short tandem repeat diversity in India and Iran compared with Europe and central Asia, suggests that southern and western Asia might be the source of this haplogroup. Haplotype frequencies of the MX1 locus of chromosome 21 distinguish Koyas and Chenchus, along with Indian caste groups, from European and eastern Asian populations. Taken together, these results show that Indian tribal and caste populations derive largely from the same genetic heritage of Pleistocene southern and western Asians and have received limited gene flow from external regions since the Holocene. The phylogeography of the primal mtDNA and Y-chromosome founders suggests that these southern Asian Pleistocene coastal settlers from Africa would have provided the inocula for the subsequent differentiation of the distinctive eastern and western Eurasian gene pools.     

Indo-Pacific population structure and evolutionary history of the coconut crab Birgus latro

Mitochondrial DNA variation was used to examine population structure in a widespread, marine-dispersed species, Birgus latro . Crabs were collected from eight locations throughout the species' Indo-Pacific distribution. Purified mtDNA from 160 individuals was cut with five restriction enzymes, revealing high haplotype diversity (0.96) and moderate nucleotide diversity (0.75%). Island populations from the Indian Ocean (Christmas I.) and Pacific Ocean were significantly different ( G _ST= 0.37) and had distinct mtDNA lineages with a net sequence divergence of 1.4%. Pacific island populations had diverged in a manner consistent with isolation by distance, with only the most peripheral populations being significantly different. The results for mtDNA are largely concordant with those from allozymes, although estimates of gene flow between the Indian and Pacific Oceans were much lower when based on mtDNA. The mtDNA phylogeny also permitted a deeper examination of the evolutionary and demographic history of Birgus latro . Long-term separation of populations is evident in the complete phylogenetic subdivision of mtDNA lineages between the Indian and Pacific Ocean populations sampled. The starlike phylogeny of alleles from the Pacific suggests a rapid population expansion in the Pacific during the Pleistocene. Including information about allele phylogeny, as well as distribution and frequency, obscured contemporary population structure, but provided unique insights into the evolutionary history of the species.     

The genetic origins of the Andaman Islanders

Mitochondrial sequences were retrieved from museum specimens of the enigmatic Andaman Islanders to analyze their evolutionary history. D-loop and protein-coding data reveal that phenotypic similarities with African pygmoid groups are convergent. Genetic and epigenetic data are interpreted as favoring the long-term isolation of the Andamanese, extensive population substructure, and/or two temporally distinct settlements. An early colonization featured populations bearing mtDNA lineage M2, and this lineage is hypothesized to represent the phylogenetic signal of an early southern movement of humans through Asia. The results demonstrate that Victorian anthropological collections can be used to study extinct, or seriously admixed populations, to provide new data about early human origins.     

Mitochondrial DNA phylogeography and population history of Meladema diving beetles on the Atlantic Islands and in the Mediterranean basin (Coleoptera,Dytiscidae)

The phylogeny and population history of Meladema diving beetles (Coleoptera, Dytiscidae) were examined using mitochondrial DNA sequence from 16S ribosomal RNA and cytochrome oxidase I genes in 51 individuals from 22 populations of the three extant species (M. imbricata endemic to the western Canary Islands, M. lanio endemic to Madeira and M. coriacea widespread in the Western Mediterranean and on the western Canaries), using a combination of phylogenetic and nested clade analyses. Four main lineages are observed within Meladema, representing the three recognized species plus Corsican populations of M. coriacea. Phylogenetic analyses demonstrate the sister relationship of the two Atlantic Island taxa, and suggest the possible paraphyly of M. coriacea. A molecular clock approach reveals that speciation within the genus occurred in the Early Pleistocene, indicating that the Atlantic Island endemics are not Tertiary relict taxa as had been proposed previously. Our results point to past population bottlenecks in all four lineages, with recent (Late-Middle Pleistocene) range expansion in non-Corsican M. coriacea and M. imbricata. Within the Canary Islands, M. imbricata seems to have independently colonized La Gomera and La Palma from Tenerife (although a colonization of La Palma from La Gomera cannot be discarded), and M. coriacea has independently colonized Tenerife and Gran Canaria from separate mainland lineages. In the Mediterranean basin this species apparently colonized Corsica on a single occasion, relatively early in its evolutionary history (Early Pleistocene), and has colonized Mallorca recently on multiple occasions. On the only island where M. coriacea and M. imbricata are broadly sympatric (Tenerife), we report evidence of bidirectional hybridization between the two species.     

Phylogeographic Analysis of Chum Salmon Oncorhynchus keta Walbaum in Asian Populations Based on mtDNA Variation

We used restriction length polymorphism (RFLP) analysis of PCR-amplified fragments of mtDNA to study the genetic structure of chum salmon populations sampled in 1993–2000 during a spawning run in five rivers: Narva (Southern Primorye), Naiba (Sakhalin Island), Sernovodnaya (Kunashir Island, Southern Kuril Islands), Ola (northwestern coast of the Sea of Okhotsk), and Anadyr' (Chukotka Peninsula). In total, 49 haplotypes were identified in 193 fish. Heterogeneity tests showed highly significant (P = 0) differences among all sample pairs. The estimated time of independent divergence of the populations or population groups is in good agreement with the time of Pleistocene glaciations. This result suggests that it is cyclic global changes during this time period that were crucial in determining the within-species divergence in chum salmon. The types of mtDNA genetic variability and mismatch distribution between haplotypes in the populations indicate that the southern regions of the Sea of Okhotsk and Sea of Japan served as refugia for chum salmon during glaciation periods.     

Phylogenic and geographic analysis of chum salmon Oncorhynchus keta (Walbaum) in Asian populations based on mitochondrial DNA variation

We used restriction length polymorphism (RFLP) analysis of PCR-amplified fragments of mtDNA to study the genetic structure of chum salmon populations sampled in 1993-2000 during a spawning run in five rivers: Narva (Southern Primorye), Naiba (Sakhalin Island), Sernovodnaya (Kunashir Island, Southern Kuril Islands), Ola (northwestern coast of the Sea of Okhotsk), and Anadyr' (Chukotka Peninsula). In total, 49 haplotypes were identified in 193 fish. Heterogeneity tests showed highly significant (P = 0) differences among all sample pairs. The estimated time of independent divergence of the populations or population groups is in good agreement with the time of Pleistocene glaciations. This result suggests that it is cyclic global changes during this time period that were crucial in determining the within-species divergence in chum salmon. The types of mtDNA genetic variability and mismatch distribution between haplotypes in the populations indicate that the southern regions of the Sea of Okhotsk and Sea of Japan served as refugia for chum salmon during glaciation periods.     

Genetic affinities of the Andaman Islanders,a vanishing human population

BACKGROUND: The Andaman Islands in the Bay of Bengal are inhabited by hunter-gatherers of unknown origin, now on the verge of extinction. The Andamanese and other Asian small-statured peoples, traditionally known as "Negritos," resemble African pygmies. However, it is generally believed that they descend from the early Australo-Melanesian settlers of Southeast Asia and that their resemblance to some Africans is due to adaptation to a similar environment, rather than shared origins.RESULTS: We analyzed mitochondrial DNA (mtDNA) sequences and RFLP polymorphisms, and Y chromosome biallelic markers and microsatellites, in present-day Andamanese of the Onge, Jarawa, and Great Andamanese tribes, and of inhabitants of the neighboring Nicobar Islands. We also analyzed mtDNA sequences from Andamanese hair samples collected by an ethnographer during 1906-1908. Living Andamanese exhibit low genetic variability that is consistent with their small population size and reproductive isolation.CONCLUSIONS: Our data indicate that the Andamanese have closer affinities to Asian than to African populations and suggest that they are the descendants of the early Palaeolithic colonizers of Southeast Asia. In contrast, the Nicobarese have genetic affinities to groups widely distributed throughout Asia today, presumably descended from Neolithic agriculturalists.     

Mitochondrial DNA variation in Nicobarese Islanders.

The aboriginal populations living in the Nicobar Islands are hypothesized to be descendants of people who were part of early human dispersals into Southeast Asia. However, analyses of ethnographic histories, languages, morphometric data, and protein polymorphisms have not yet resolved which worldwide populations are most closely related to the Nicobarese. Thus, to explore the origins and affinities of the Nicobar Islanders, we analyzed mitochondrial DNA (mtDNA) hypervariable region 1 sequence data from 33 Nicobarese Islanders and compared their mtDNA haplotypes to those of neighboring East Asians, mainland and island Southeast Asians, Indians, Australian aborigines, Pacific Islanders, and Africans. Unique Nicobarese mtDNA haplotypes, including five Nicobarese mtDNA haplotypes linked to the COII/tRNA(Lys) 9-bp deletion, are most closely related to mtDNA haplotypes from mainland Southeast Asian Mon-Kmer-speaking populations (e.g., Cambodians). Thus, the dispersal of southern Chinese into mainland Southeast Asia may have included a westward expansion and colonization of the islands of the Andaman Sea.     

Kinorhynchs from the Andaman Islands

Echinoderes andamanensis sp. nov. is described from the Andaman Islands (Bay of Bengal, Indian Ocean). Unlike most members of this genus, this new species lacks middorsal spines. It is further distinguished by the presence of lateral spines on segments 4, 10 and 11 in the female and 4, 10–12 in the inale. Collected with E. andamanensis were specimens of E. ehlersi previously known only from a single specimen collected in 1885 in Zanzibar. The Andaman Island females have shorter spines than the males. Additional species include Catena gerlachi , previously known only from Walcair, India. A single juvenile exuvium of Pynophyes sp. was also found. The taxonomic relationships of the species and other members of the genus are discussed.     

Population genetic structure of skipjack tuna Katsuwonus pelamis from the Indian coast using sequence analysis of the mitochondrial DNA D-loop region

Genetic structure of skipjack tuna Katsuwonus pelamis from the Indian region was investigated using sequence data of mitochondrial DNA (mtDNA) D-loop region. A total of 315 individuals were sampled from six major fishing grounds around the east and west coasts of India including the Andaman (Port Blair) and Lakshadweep (Minicoy) Islands. Nucleotide and gene diversities were high in all the sample collections. Significant genetic heterogeneity was observed for the mtDNA sequence data among sites (φ(ST) = 0·0273, P < 0·001). Analysis of molecular variance (AMOVA) showed significant genetic variation among four groups (φ(CT) = 0·0261, P < 0·05) which was also supported by spatial AMOVA results. The null hypothesis of single panmictic population of K. pelamis along the Indian coast can thus be rejected. Phylogenetic analysis of the mtDNA sequence data showed the presence of four clades of K. pelamis in the Indian waters. There was no clear pattern, however, of haplotypes and geographic location among samples. The results of this study suggest the occurrence of four genetically differentiated groups of K. pelamis across the coastal waters of India.     

Evolutionary history of the mtDNA 9-bp deletion in Chinese populations and its relevance to the peopling of east and southeast Asia

In total, 1218 Chinese from twelve ethnic groups and nine Han geographic groups were screened for the mtDNA 9-bp deletion motif. The frequency of the 9-bp deletion in all samples was 14.7% but ranged from 0% to 32% in the various ethnic groups. Three individuals had a triplication of the 9-bp segment. Phylogenetic and demographic analyses of the mtDNA hypervariable segment 1 (HVS 1) sequences suggest that the 9-bp deletion occurred more than once in China. The majority of the Chinese deletion haplotypes (about 90%) have a common origin as a mutational event following an initial expansion of modern humans in eastern Asia. Other deletion haplotypes and the three haplotypes with a 9-bp triplication may have arisen independently in the Chinese, presumably by replication error. HVS1 haplotype analysis suggests two possible migration routes of the 9-bp deletion in east and southeast Asia. Both migrations originated in China with one route leading to the Pacific Islands via Taiwan, the other to southeast Asia and possibly the Nicobar Islands. Along both routes of peopling, a decrease in HVSI diversity of the mtDNA haplotypes is observed. The "Polynesian motif (16217T/C, 16247A/G, and 16261C/T)" and the 16140T/C, 16266C/A, or C/G polymorphisms appear specific to each migration route.     

Phylogeography of northern Dolly Varden Salvelinus malma (Salmoniformes: Salmonidae) from Asia and North America: An analysis based on the mitochondrial DNA genealogy

Spawning in habitats affected by Pleistocene glacial advances over most of its natural range, northern Dolly Varden Salvelinus malma malma typifies Arctic fauna distributed in northeastern Asia and northwestern North America. We reconstructed a genealogy of mtDNA haplotypes from 27 Alaskan and Asian populations to study the influence of historical events on the phylogeography and contemporary population genetic structure. Analysis of molecular variance partitioned most of the mtDNA variability to the intrapopulation component (72.5%) with much reduced differences between populations (21.1%) and regions (6.4%). Similar patterns of variation apparent from hierarchical diversity and nested clade phylogeographical analysis (NCPA) of mtDNA haplotypes identify weak spatial differentiation and low levels of divergence. These findings suggest (1) that demographic history has been influenced by historical range expansions and recent isolation by distance, (2) that present populations from Asia and North America were colonized from one main Beringian Refugium, and (3) that this taxon’s ancestral population probably experienced a bottleneck in the Beringian Refugium during the late Pleistocene (Wisconsin) glacial period. The genealogical and NCPA analyses, and mismatch distribution of S. m. malma mtDNA haplotypes do not confirm the assumptions about presence of the two refugia on the territories of the Beringian Land, in which allopatric S. m. malma ancestral populations evolved, and independent origin of the Sea of Okhotsk populations.     

Out of Africa: the slow train to australasia

We used mitochondrial DNA (mtDNA) sequences to test biogeographic hypotheses for Patiriella exigua (Asterinidae), one of the world's most widespread coastal sea stars. This small intertidal species has an entirely benthic life history and yet occurs in southern temperate waters of the Atlantic, Indian, and Pacific oceans. Despite its abundance around southern Africa, southeastern Australia, and several oceanic islands, P. exigua is absent from the shores of Western Australia, New Zealand, and South America. Phylogenetic analysis of mtDNA sequences (cytochrome oxidase I, control region) indicates that South Africa houses an assemblage of P. exigua that is not monophyletic (P = 0.04), whereas Australian and Lord Howe Island specimens form an interior monophyletic group. The placement of the root in Africa and small genetic divergences between eastern African and Australian haplotypes strongly suggest Pleistocene dispersal eastward across the Indian Ocean. Dispersal was probably achieved by rafting on wood or macroalgae, which was facilitated by the West Wind Drift. Genetic data also support Pleistocene colonization of oceanic islands (Lord Howe Island, Amsterdam Island, St. Helena). Although many biogeographers have speculated about the role of long-distance rafting, this study is one of the first to provide convincing evidence. The marked phylogeographic structure evident across small geographic scales in Australia and South Africa indicates that gene flow among populations may be generally insufficient to prevent the local evolution of monophyly. We suggest that P. exigua may rely on passive mechanisms of dispersal.     

Multilocus genetic diversity and historical biogeography of the endemic wall lizard from Ibiza and Formentera,Podarcis pityusensis (Squamata: Lacertidae)

Two monophyletic sister species of wall lizards inhabit the two main groups of Balearic Islands: Podarcis lilfordi from islets and small islands around Mallorca and Menorca and Podarcis pityusensis from Ibiza, Formentera and associated islets. Genetic diversity within the endangered P. lilfordi has been well characterized, but P. pityusensis has not been studied in depth. Here, 2430 bp of mtDNA and 15 microsatellite loci were analysed from P. pityusensis populations from across its natural range. Two main genetic groupings were identified, although geographical structuring differed slightly between the mtDNA and the nuclear loci. In general, individuals from islets/islands adjacent to the main island of Ibiza were genetically distinct from those from Formentera and the associated Freus islands for both mtDNA and the nuclear loci. However, most individuals from the island of Ibiza were grouped with neighbouring islets/islands for nuclear loci, but with Formentera and Freus islands for the mitochondrial locus. A time‐calibrated Bayesian tree was constructed for the principal mitochondrial lineages within the Balearics, using the multispecies coalescent model, and provided statistical support for divergence of the two main P. pityusensis lineages 0.111–0.295 Ma. This suggests a mid‐late Pleistocene intraspecific divergence, compared with an early Pleistocene divergence in P. lilfordi, and postdates some major increases in sea level between 0.4 and 0.6 Ma, which may have flooded Formentera. The program IMa2 provided a posterior divergence time of 0.089–0.221 Ma, which was similar to the multispecies coalescent tree estimate. More significantly, it indicated low but asymmetric effective gene copy migration rates, with higher migration from Formentera to Ibiza populations. Our findings suggest that much of the present‐day diversity may have originated from a late Pleistocene colonization of one island group from the other, followed by allopatric divergence of these populations. Subsequent gene flow between these insular groups seems likely to be explained by recent human introductions. Two evolutionary significant units can be defined for P. pityusensis but these units would need to exclude the populations that have been the subjects of recent admixture.     

The Phylogeography of Y-Chromosome Haplogroup H1a1a-M82 Reveals the Likely Indian Origin of the European Romani Populations

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 Indian-specific 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.