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Post by Admin on Aug 26, 2019 18:01:05 GMT
Discussion The genetically, temporally, and isotopically heterogeneous composition of the groups at Roopkund Lake was unanticipated from the context in which the skeletons were found. Radiocarbon dating reveals at least two key phases of deposition of human remains separated by around one thousand years and with significant heterogeneity in the dates for the earlier individuals indicating that they could not all have died in a single catastrophic event.  Combining multiple lines of evidence, we suggest a possible explanation for the origin of at least some of the Roopkund_A individuals. Roopkund Lake is not situated on any major trade route, but it is on a present-day pilgrimage route—the Nanda Devi Raj Jat pilgrimage which today occurs every 12 years (Fig. 1a). As part of the event, pilgrims gather for worship and celebration along the route. Reliable descriptions of the pilgrimage ritual do not appear until the late-19th century, but inscriptions in nearby temples dating to between the 8th and 10th centuries suggest potential earlier origins20. We view the hypothesis of a mass death during a pilgrimage event as a plausible explanation for at least some of the individuals in the Roopkund_A cluster.  The Roopkund_B cluster is more puzzling. It is tempting to hypothesize that the Roopkund_B individuals descend from Indo-Greek populations established after the time of Alexander the Great, who may have contributed ancestry to some present-day groups like the Kalash21. However, this is unlikely, as such a group would be expected to have admixture with groups with more typical South Asian ancestry (as the Kalash do), or would be expected to be inbred and to have relatively low genetic diversity. However, the Roopkund_B individuals have evidence for neither pattern (Supplementary Note 9). Combining different lines of evidence, the data suggest instead that what we have sampled is a group of unrelated men and women who were born in the eastern Mediterranean during the period of Ottoman political control. As suggested by their consumption of a predominantly terrestrial, rather than marine-based diet, they may have lived in an inland location, eventually traveling to and dying in the Himalayas. Whether they were participating in a pilgrimage, or were drawn to Roopkund Lake for other reasons, is a mystery. It would be surprising for a Hindu pilgrimage to be practiced by a large group of travelers from the eastern Mediterranean where Hindu practices have not been common; Hindu practice in this time might be more plausible for a southeast Asian individual with an ancestry type like that seen in the Roopkund_C individual. Given that the Roopkund_B and Roopkund_C individuals died only in the last few centuries, an important direction for future investigation will be to carry out archival research to determine if there were reports of large foreign traveling parties dying in the region over the last few hundred years.  Taken together, these results have produced meaningful insights about an enigmatic ancient site. More generally, this study highlights the power of biomolecular analyses to obtain rich information about the human story behind archaeological deposits that are so highly disturbed that traditional archaeological methods are not as informative. Nature Communications volume 10, Article number: 3670 (2019) |
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Post by Admin on Sept 9, 2019 18:03:49 GMT
We report an ancient genome from the Indus Valley Civilization (IVC). The individual we sequenced fits as a mixture of people related to ancient Iranians (the largest component) and Southeast Asian hunter-gatherers, a unique profile that matches ancient DNA from 11 genetic outliers from sites in Iran and Turkmenistan in cultural communication with the IVC. These individuals had little if any Steppe pastoralist-derived ancestry, showing that it was not ubiquitous in northwest South Asia during the IVC as it is today. The Iranian-related ancestry in the IVC derives from a lineage leading to early Iranian farmers, herders, and hunter-gatherers before their ancestors separated, contradicting the hypothesis that the shared ancestry between early Iranians and South Asians reflects a large-scale spread of western Iranian farmers east. Instead, sampled ancient genomes from the Iranian plateau and IVC descend from different groups of hunter-gatherers who began farming without being connected by substantial movement of people.  The mature Indus Valley Civilization (IVC), also known as the Harappan Civilization, was spread over northwestern South Asia from 2600 to 1900 BCE and was one of the first large-scale urban societies of the ancient world, characterized by systematic town planning, elaborate drainage systems, granaries, and standardization of weights and measures. The inhabitants of the IVC were cosmopolitan, with multiple cultural groups living together in large regional urban centers like Harappa (Punjab), Mohenjo-daro (Sindh), Rakhigarhi (Haryana), Dholavira (Kutch/Gujarat), and Ganweriwala (Cholistan) (Figure 1A) (Mughal, 1990, Possehl, 1982, Possehl, 1990, Shaffer and Lichtenstein, 1989). Rakhigarhi is one of the largest known IVC sites (Figures 1B and 1C), and seven dates from charcoal at depths of 9–23 m have point estimates of 2800–2300 BCE, which largely fall within the mature phase of the IVC (Shinde et al., 2018, Vahia et al., 2016). As part of the archaeological effort, we attempted to generate ancient DNA data for a subset of the excavated burials.  Figure 1 Archeological Context of the Individual Who Yielded Ancient DNA Results In dedicated clean rooms, we obtained powder from 61 skeletal samples from the Rakhigarhi cemetery, which lies ∼1 km west of the ancient town (Table S1). We extracted DNA (Dabney et al., 2013, Korlević et al., 2015) and converted the extracts into libraries (Rohland et al., 2015), some of which we treated with uracil-DNA glycosylase (UDG) to greatly reduce the error rates associated with the characteristic cystosine-to-uracil lesions of ancient DNA. We enriched all libraries for sequences overlapping both the mitochondrial genome and ∼3,000 targeted nuclear positions (Olalde et al., 2018) and sequenced the enriched libraries either on an Illumina NextSeq500 instrument using paired 2 × 76 base pair (bp) reads or on Illumina HiSeq X10 instruments using paired 2 × 150 bp reads. After trimming adapters and merging sequences overlapping by at least 15 bp (allowing up to one mismatch), we mapped to both the mitochondrial genome rsrs (Behar et al., 2012) and the human genome reference hg19 (Li and Durbin, 2010) (Table S1). After inspecting the screening results, we enriched a subset of libraries for ∼1.2 million SNPs and sequenced the enriched libraries and processed the data as described above mapping to hg19 only (Fu et al., 2015, Haak et al., 2015, Mathieson et al., 2015). For the most promising sample, which had the genetic identification code I6113 and the archaeological skeletal code RGR7.3, BR-01, HS-02 (Figures 1B and S1), we created, enriched, and sequenced a total of 109 double- and single-stranded libraries from five extractions (Meyer et al., 2012, Glocke and Meyer, 2017, Rohland et al., 2018, Gansauge et al., 2017) (only the initial library was UDG treated). After removing 41 libraries (from one extraction) that had significantly lower coverage, and merging data from the remaining 68 libraries, we had 86,440 SNPs covered at least once. Almost all of these 68 libraries showed cytosine-to-thymine mismatch rates to the human reference genome in the final 5′ and 3′ nucleotides greater than 10%, consistent with the presence of authentic ancient DNA (“ancient DNA damage”). However, when we stratified the pooled data by sequence length, we found lower damage rates particularly for sequences of length >50 bp (Figure S2; STAR Methods). This was suggestive of the presence of contamination, and to increase confidence that our analyses were not biased by contamination, we restricted the data to molecules that showed cytosine-to-thymine mismatches characteristic of ancient DNA. This resulted in data at 31,760 SNPs. The ratio of damage-restricted sequences mapping to the Y chromosome to sequences mapping to both the Y and X chromosomes was in the range expected for a female. After building a mitochondrial DNA consensus using damage-restricted sequences, we determined that its haplogroup was U2b2, which is absent in whole mitochondrial genomes sequences available from about 400 ancient Central Asians; today, this specific haplogroup is nearly exclusive to South Asia (Narasimhan et al., 2019). |
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Post by Admin on Sept 10, 2019 19:15:14 GMT
 Figure S2 Quality Control to Identify a Subset of Authentic Sequences, Related to STAR Methods In principal-component analysis (PCA) (Figure 2A), I6113 projects onto a previously defined genetic gradient represented in 11 individuals from two sites in Central Asia in cultural contact with the IVC (3 from Gonur in present-day Turkmenistan and 8 from Shahr-i-Sokhta in far eastern Iran); these individuals were previously identified via a formal statistical procedure as significant outliers relative to the majority of samples at these two sites (they represent only 25% of the total) and were called the Indus Periphery Cline (Narasimhan et al., 2019). Despite having only modest SNP coverage, the error bars for the positioning of I6113 in the PCA are sufficiently small to show that this individual is not only significantly different in ancestry from the primary ancient populations of Bronze Age Gonur and Shahr-i-Sokhta but also does not fall within the variation of present-day South Asians. We obtained qualitatively consistent results when analyzing the data using ADMIXTURE (Alexander et al., 2009), with I6113 again similar to the 11 outlier individuals in harboring a mixture of ancestry related to ancient Iranians and tribal southern Indians. None of these individuals had evidence of “Anatolian farmer-related” ancestry, a term we use to refer to the lineage found in ancient genomes from 7th millennium BCE farmers from Anatolia (Mathieson et al., 2015). This Anatolian farmer-related ancestry was absent in all sampled ancient genomes from Iranian herders or hunter-gatherers dating from the 12th through the 8th millennia BCE, who instead carried a very different ancestry profile also present in mixed form in South Asia that we call “Iranian related” (Broushaki et al., 2016, Lazaridis et al., 2016).  Figure 2 Population Genetic Analysis We used qpAdm to test highly divergent populations that have been shown to be effective for modeling diverse West and South Eurasian groups as potential sources for I6113 (Narasimhan et al., 2019). If one of these population fits, it does not mean it is the true source; instead, it means that it and the true source population are consistent with descending without mixture from the same homogeneous ancestral population that potentially lived thousands of years before. The only fitting two-way models were mixtures of a group related to herders from the western Zagros mountains of Iran and also to either Andamanese hunter-gatherers (73% ± 6% Iranian-related ancestry; p = 0.103 for overall model fit) or East Siberian hunter-gatherers (63% ± 6% Iranian-related ancestry; p = 0.24) (the fact that the latter two populations both fit reflects that they have the same phylogenetic relationship to the non-West Eurasian-related component of I6113 likely due to shared ancestry deeply in time). This is the same class of models previously shown to fit the 11 outliers that form the Indus Periphery Cline (Narasimhan et al., 2019), and indeed, I6113 fits as a genetic clade with the pool of Indus Periphery Cline individuals in qpAdm (p = 0.42). Multiple lines of evidence suggest that the genetic similarity of I6113 to the Indus Periphery Cline individuals is due to gene flow from South Asia rather than in the reverse direction. First, of the 44 individuals with good-quality data we have from Gonur and Shahr-i-Sokhta, only 11 (25%) have this ancestry profile; it would be surprising to see this ancestry profile in the one individual we analyzed from Rakhigarhi if it was a migrant from regions where this ancestry profile was rare. Second, of the three individuals at Shahr-i-Sokhta who have material culture linkages to Baluchistan in South Asia, all are IVC Cline outliers, specifically pointing to movement out of South Asia (Narasimhan et al., 2019). Third, both the IVC Cline individuals and the Rakhigarhi individual have admixture from people related to present-day South Asians (ancestry deeply related to Andamanese hunter-gatherers) that is absent in the non-outlier Shahr-i-Sokhta samples and is also absent in Copper Age Turkmenistan and Uzbekistan (Narasimhan et al., 2019), implying gene flow from South Asia into Shahr-i-Sokhta and Gonur, whereas our modeling does not necessitate reverse gene flow. Based on these multiple lines of evidence, it is reasonable to conclude that individual I6113’s ancestry profile was widespread among people of the IVC at sites like Rakhigarhi, and it supports the conjecture (Narasimhan et al., 2019) that the 11 outlier individuals in the Indus Periphery Cline are migrants from the IVC living in non-IVC towns. We rename the genetic gradient represented in the combined set of 12 individuals the “IVC Cline” and then use higher-coverage individuals from this cline in lieu of I6113 to carry out fine-scale modeling of this ancestry profile. Modeling the individuals on the IVC Cline using the two-way models previously fit for diverse present-day South Asians (Narasimhan et al., 2019), we find that, as expected from the PCA, it does not fit the two-way mixture that drives variation in modern South Asians as it is significantly depleted in Steppe pastoralist-related ancestry adjusting for its proportion of Iranian-related ancestry (p = 0.018 from a two-sided Z test). Modeling the IVC Cline using the simpler two-way admixture model without Steppe pastoralist-derived ancestry previously shown to fit the 11 outliers (Narasimhan et al., 2019), I6113 falls on the more Iranian-related end of the gradient, revealing that Iranian-related ancestry extended to the eastern geographic extreme of the IVC and was not restricted to individuals at its Iranian and Central Asian periphery. The estimated proportion of ancestry related to tribal groups in southern India in I6113 is smaller than in present-day groups, suggesting that since the time of the IVC there has been gene flow into the part of South Asia where Rakhigarhi lies from both the northwest (bringing more Steppe ancestry) and southeast (bringing more ancestry related to tribal groups in southern India). The genetic profile that we document in this individual, with large proportions of Iranian-related ancestry but no evidence of Steppe pastoralist-related ancestry, is no longer found in modern populations of South Asia or Iran, providing further validation that the data we obtained from this individual reflects authentic ancient DNA. To obtain insight into the origin of the Iranian-related ancestry in the IVC Cline, we co-modeled the highest-coverage individual from the IVC Cline, Indus_Periphery_West (who also happens to have one of the highest proportions of Iranian-related ancestry) with other ancient individuals from across the Iranian plateau representing early hunter-gatherer and food-producing groups: a ∼10,000 BCE individual from Belt Cave in the Alborsz Mountains, a pool of ∼8000 BCE early goat herders from Ganj Dareh in the Zagros Mountains, a pool of ∼6000 BCE farmers from Hajji Firuz in the Zagros Mountains, and a pool of ∼4000 BCE farmers from Tepe Hissar in Central Iran. Using qpGraph (Patterson et al., 2012), we tested all possible simple trees relating the Iranian-related ancestry component of these groups, accounting for known admixtures (Anatolian farmer-related admixture into Hajji Firuz and Tepe Hissar and Andamanese hunter-gatherer-related admixture in the IVC Cline) (Figure S3), using an acceptance criterion for the model fitting that the maximum |Z| scores between observed and expected f-statistics was <3 or that the Akaike Information Criterion (AIC) was within 4 of the best-fit (Burnham and Anderson, 2004). The only consistently fitting models specified that the Iranian-related lineage contributing to the IVC Cline split from the Iranian-related lineages sampled from ancient genomes of the Iranian plateau before the latter separated from each other (Figure 3 represents one such model consistent with our data). We confirmed this result by using symmetry tests that we applied first to stimulated data (Figure S4) and then evaluated the relationships among the Iranian-related lineages, correcting for the effects of Anatolian farmer-related, Andamanese hunter-gatherer-related, and West Siberian hunter-gatherer-related admixture (STAR Methods). We find that 94% of the resulting trees supported the Iranian-related lineage in the IVC Cline being the first to separate from the other lineages, consistent with our modeling results. |
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Post by Admin on Sept 11, 2019 18:16:41 GMT
 Figure S3 Phylogenies of Iranian-Related Populations Tested for Fits to the Data, Related to STAR Methods Our evidence that the Iranian-related ancestry in the IVC Cline diverged from lineages leading to ancient Iranian hunter-gatherers, herders, and farmers prior to their ancestors’ separation places constraints on the spread of Iranian-related ancestry across the combined region of the Iranian plateau and South Asia, where it is represented in all ancient and modern genomic data sampled to date. The Belt Cave individual dates to ∼10,000 BCE, definitively before the advent of farming anywhere in Iran, which implies that the split leading to the Iranian-related component in the IVC Cline predates the advent of farming there as well (Figure 3). Even if we do not consider the results from the low-coverage Belt Cave individual, our analysis shows that the Iranian-related lineage present in the IVC Cline individuals split before the date of the ∼8000 BCE Ganj Dareh individuals, who lived in the Zagros mountains of the Iranian plateau before crop farming began there around ∼7000–6000 BCE. Thus, the Iranian-related ancestry in the IVC Cline descends from a different group of hunter-gatherers from the ancestors of the earliest known farmers or herders in the western Iranian plateau. We also highlight a second line of evidence against the hypothesis that eastward migrations of descendants of western Iranian farmers or herders were the source of the Iranian-related ancestry in the IVC Cline. An independent study has shown that all ancient genomes from Neolithic and Copper Age crop farmers of the Iranian plateau harbored Anatolian farmer-related ancestry not present in the earlier herders of the western Zagros (Narasimhan et al., 2019). This includes western Zagros farmers (∼59% Anatolian farmer-related ancestry at ∼6000 BCE at Hajji Firuz) and eastern Alborsz farmers (∼30% Anatolian farmer-related ancestry at ∼4000 BCE at Tepe Hissar). That the 12 sampled individuals from the IVC Cline harbored negligible Anatolian farmer-related ancestry thus provides an independent line of evidence (in addition to their deep-splitting Iranian-related lineage that has not been found in any sampled ancient Iranian genomes to date) that they did not descend from groups with ancestry profiles characteristic of all sampled Iranian crop-farmers (Narasimhan et al., 2019). While there is a small proportion of Anatolian farmer-related ancestry in South Asians today, it is consistent with being entirely derived from Steppe pastoralists who carried it in mixed form and who spread into South Asia from ∼2000–1500 BCE (Narasimhan et al., 2019).  Figure 3 Best-Fitting Admixture Graph Relating Populations with Iranian-Related Ancestry  Figure S4 Simulated Phylogeny, Related to STAR Methods Discussion These findings suggest that in South Asia as in Europe, the advent of farming was not mediated directly by descendants of the world’s first farmers who lived in the fertile crescent. Instead, populations of hunter-gatherers—in Eastern Anatolia in the case of Europe (Feldman et al., 2019) and in a yet-unsampled location in the case of South Asia—began farming without large-scale movement of people into these regions. This does not mean that movements of people were unimportant in the introduction of farming economies at a later date; for example, ancient DNA studies have documented that the introduction of farming to Europe after ∼6500 BCE was mediated by a large-scale expansion of Western Anatolian farmers who descended largely from early hunter-gatherers of Western Anatolia (Feldman et al., 2019). It is possible that in an analogous way, an early farming population expanded dramatically within South Asia, causing large-scale population turnovers that helped to spread this economy within the region. Whether this occurred is still unverified and could be determined through ancient DNA studies from just before and after the farming transitions in South Asia. Our results also have linguistic implications. One theory for the origins of the now-widespread Indo-European languages in South Asia is the “Anatolian hypothesis,” which posits that the spread of these languages was propelled by movements of people from Anatolia across the Iranian plateau and into South Asia associated with the spread of farming. However, we have shown that the ancient South Asian farmers represented in the IVC Cline had negligible ancestry related to ancient Anatolian farmers as well as an Iranian-related ancestry component distinct from sampled ancient farmers and herders in Iran. Since language proxy spreads in pre-state societies are often accompanied by large-scale movements of people (Bellwood, 2013), these results argue against the model (Heggarty, 2019) of a trans-Iranian-plateau route for Indo-European language spread into South Asia. However, a natural route for Indo-European languages to have spread into South Asia is from Eastern Europe via Central Asia in the first half of the 2nd millennium BCE, a chain of transmission that did occur as has been documented in detail with ancient DNA. The fact that the Steppe pastoralist ancestry in South Asia matches that in Bronze Age Eastern Europe (but not Western Europe [de Barros Damgaard et al., 2018, Narasimhan et al., 2019]) provides additional evidence for this theory, as it elegantly explains the shared distinctive features of Balto-Slavic and Indo-Iranian languages (Ringe et al., 2002). Our analysis of data from one individual from the IVC, in conjunction with 11 previously reported individuals from sites in cultural contact with the IVC, demonstrates the existence of an ancestry gradient that was widespread in farmers to the northwest of peninsular India at the height of the IVC, that had little if any genetic contribution from Steppe pastoralists or western Iranian farmers or herders, and that had a primary impact on the ancestry of later South Asians. While our study is sufficient to demonstrate that this ancestry profile was a common feature of the IVC, a single sample—or even the gradient of 12 likely IVC samples we have identified—cannot fully characterize a cosmopolitan ancient civilization. An important direction for future work will be to carry out ancient DNA analysis of additional individuals across the IVC range to obtain a quantitative understanding of how the ancestry of IVC people was distributed and to characterize other features of its population structure. Published:September 05, 2019 DOI:https://doi.org/10.1016/j.cell.2019.08.048 |
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Post by Admin on Jun 8, 2020 0:03:23 GMT
Y-STR Haplogroup Diversity in the Jat Population Reveals Several Different Ancient Origins David G. Mahal1,2* and Ianis G. Matsoukas1 Front. Genet., 20 September 2017 | doi.org/10.3389/fgene.2017.00121Introduction Population and Demographics The Jats represent one of the largest ethnic groups that has evolved in the northwest region of the Indian subcontinent—India and Pakistan—over several thousand years. Since the partition of India in 1947, Hindu and Sikh Jats have lived primarily in India, and the Muslim Jats have lived primarily in Pakistan. In 2012, the Jat population in India—mostly Hindus and Sikhs—was reported to be 82.5 million people (Chatterji, 2012). The last time the population was surveyed according to caste–in the 1931 Census of India–the Jats belonged to three main religions: Hinduism 47%, Islam 33%, and Sikhism 20% (Burdak, 2016). Assuming the ratio among religions has stayed about the same (i.e., 33% for Islam and 67% combined for Hinduism and Sikhism), the population of Muslim Jats in 2012 can be extrapolated to about 40.6 million (82.5 million/67 × 33). On this basis, the total population of all Jats in the Indian subcontinent is estimated to be around 123 million people, roughly equal to the combined population of France, Spain, and Portugal.  Archeological Evidence The origins of the Indus Valley Civilization—also known as the Harrapan Civilization—can be traced to 7,380–6,201 BCE in northwestern India (Khandekar, 2012). A recent discovery of a large Indus Valley site was made in Rakhighari, about 160 km from New Delhi. Its origins go back to about 5000 BCE (Subramanian and Khan, 2016). This ancient civilization flourished in the third millennium BCE (Harari, 2015), and its people were known as the earliest agriculturists in South Asia (Harris, 1996). Originally the Jats were pastoralists (Khazanov and Wink, 2001), and gradually became farmers. Although farming settlements emerged in the Indus Valley Civilization about 4,000 BCE (Violatti, 2013), and Jats have been firmly settled as agriculturists in the same geographical region, a connection between the two has not been explored thoroughly. Apparently, this is because there is no conclusive written history of the people of the Indian subcontinent when we look back more than about 2,500 years. As a result, the deep ancestry of the Jat people has remained a mystery for a long time. Historical Perspectives Among the earliest available books from India—written in Sanskrit—that provide some glimpses of history are the Rigveda, composed between 1,500 and 500 BCE (Flood, 1996), and the Mahabharata, composed between 400 BCE and 400 CE (Molloy, 2008). This textual evidence contains some references to the existence of agriculture in the area, and mentions people known as the Srinjaya—meaning, sons of the sickle or farmers (Hewitt, 1894). Some early Greek and Roman historians had acquired fragments of information about India from soldiers and merchants in the Persian Empire. But there is no reliable written history of the Indian subcontinent before Alexander the Great's campaign of India in 327 BCE (Smith, 1921). Although archeology has shed some light about the distant past—and even this record is incomplete—written history of India goes back only about 2,500 years. More recently, numerous books have been written about Indian history and scholarship has been attempted over the origins of the Jats. Several historians have asserted that Jats were descendants of Indo-Aryans (Risley, 1915; Vaidya, 1921; Singh, 1963; Joon, 1967; Dahiya, 1980; Jindal, 1992; Qanungo, 2003), or Indo-Scythians (Elphinstone, 1841; Cunningham, 1871; Tod, 1920; Mahil, 1955; Marshall, 1960; Dhillon, 1994; Nijjar, 2008). The focus of most historians has been on the Indo-Aryan migrations to north India, which started around 1750 BCE, and the arrival of Indo-Scythians later around 200 BCE. The historical debate between the Aryan and Scythian origins of the Jats has continued (Panwar, 1993). In the scientific community as well, there are varied opinions regarding the Indo-Aryan migrations to India (Wells et al., 2001; Cordaux et al., 2004; Metspalu et al., 2011). A Pioneer Study Based on Ethnography In the early days of anthropology, craniometry seemed to offer a solution to the study of antiquity of humans, and attention was directed mainly at the examination of skulls that were excavated. This led to anthropometry, a process of measuring various parts of living humans. Sir Herbert Risley, who was in-charge of the Census of India, introduced anthropometry in India in 1886, and became a pioneer in the application of scientific methods to classify ethnic groups of the country. Based on their tall stature, a long head, fair complexion, and narrow nose, the Jats were classified as Indo-Aryan, and groups with a medium stature, a broad head, fair complexion, and a moderately fine nose, were classified as Scytho-Dravidian (Risley, 1915). The study received criticism, but it opened new fields of enquiry about the people of the subcontinent. Tracing Deep Ancestry We can identify our progenitors going back a few hundred years with traditional genealogical methods using records of family history. Beyond that, tracing ancestry is complicated because there is generally no documentation. New methods are now available based on recent developments in DNA science. Because DNA is inherited from our parents, it is possible to track the genes going back thousands of years and determine where our ancestors came from. Genetic tests allow us to trace the origins and paths of ancestors. In DNA testing, two kinds of markers on the DNA strand are assessed: short tandem repeats (STRs), and single nucleotide polymorphisms (SNPs). The STRs are found on the Y-chromosome (Y-STRs) and used exclusively for tracing male lines of heredity. The SNPs are found on the Y-chromosome and in MT-DNA. They are used to trace male and female lines of heredity. The result of the test is a set of numbers, referred to as the haplotype, which is used to identify the haplogroup of an individual. Thus, the haplogroup represents a group of people who have inherited common genetic characteristics from the same most recent common ancestor (MRCA). All humans belong to haplogroups which are designated according to their Y-DNA and MT-DNA. The geographic origins of a Y-chromosome haplogroup can be deciphered from the phylogenetic tree of mankind maintained by the International Society of Genetic Genealogy (ISOGG, 2016). By identifying Y-chromosome haplogroups and their geographic origins, this study has shown that: (a) the genetic origins of the Jats can be traced to at least nine different ancestors and geographical areas of this world, and (b) as a result, this ethnic group did not emerge from a single ancient population such as, the Indo-Aryans or Indo-Scythians. |
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