UPSC GK: Understanding Aryan Debate (HISTORY)

The study

Titled ‘The Genomic Formation of South and Central Asia’, the study looks at “ancient DNA” from 357 individuals from Central and South Asia to say that there was indeed some kind of migration into India around the 2nd millennium BCE, towards the end of the Indus Valley Civilisation. Overall, the dataset included 612 ancient individuals that were then co-analysed with genome-wide data from present-day individuals. The study which is yet to be peer-reviewed does not use the term ‘Aryan’. It says Steppe pastoralists around the Volga and Don rivers in Russia moved towards India encountering the Indus Valley population. “[T]hey mixed with a more southern population that we document at multiple sites as outlier individuals exhibiting a distinctive mixture of ancestry related to Iranian agriculturalists and South Asian hunter-gatherers,” the study states.

Mixing of population groups

The study is based on the understanding that present-day South Asians have descended from a mixture of two highly divergent populations: Ancestral North Indians (ANI) and Ancestral South Indians (ASI). The research reveals a complex set of genetic sources that combine three potential groupings that mixed together in various ways to create the ANI and ASI. The first are the South Asian hunter-gatherers, who are described in the study as AASI or Ancient Ancestral South Indians. These were the Onge or the indigenous population of the Andaman Islands. Second, is the Iranian agriculturalists, represented by 8th millennium BCE pastoralists from the Zagros mountains, who were known to have come to the subcontinent.

Then, there are the Steppe pastoralists, often loosely referred to as the ‘Aryans’, who inhabited the vast Central Asia grasslands. The study reveals that in the beginning, the Indus Valley population was a result of the mixing of first and second groups. Then the Steppe pastoralists moved Southwards and mixed with the Indus Valley population. Further, people from Indus Valley moved southwards to merge with the South Asian hunter-gatherers to form the ASI. In the meantime, a genome admixture took place in the north between the population from the Steppe and the Indus Valley to create the ANI population stock. Later, the ANI and ASI continued to mix with each other to create almost the entire ancestry of South Asian population. The study works with the Indus Valley Periphery data and uses data of individuals from Central Asian sites that they believe to be related to the Indus Valley people, even as genetic data from the Harappan sites are yet to be released.

Another finding is the connection between the Steppe pastoralists and the priestly castes, and cultures of North India. The research finds that 10 out of 140 Indian groups studied have a higher amount of Steppe ancestry than Indus Valley ancestry, the highest two were ‘Brahmin-Tiwari’ and ‘Brahmin-UP’. The study points out that “although the enrichment for Steppe ancestry is not found in southern Indian groups, the Steppe enrichment in the northern groups is striking as Brahmins and Bhumihars are among the traditional custodians of texts written in early Sanskrit”.

Significance

According to author and former Businessworld editor Tony Joseph, who has written extensively on early Indians, the study is “pathbreaking” because DNA from 612 ancient individuals were co-analysed with DNA from present-day individuals and “this is what makes this study dramatically different from previous studies”. “In the last five years, the techniques for extracting and analysing ancient DNA has improved by leaps and bounds, and this is helping us understand our prehistory far better, not just in South Asia, but around the world. For example, in the last five years, we have learnt that Europe went through two major mass migrations that changed their demography, and in the same period, we have also learnt that the Americas, before European arrivals, were peopled by at least four migrations from Asia. So the findings about South Asia are just one part of the revolution that ancient DNA is bringing to prehistory across the world.”

Essentially, Joseph points out, the study shows that there are no “pure” people anywhere — except perhaps in some very isolated and remote places such as some of the Andaman and Nicobar islands. “We are all mixed. Almost all parts of the world have seen repeated mass migrations that have deeply impacted their demography and India is no exception. The genetic studies should be liberating in a way because it should make us aware that we are all interconnected.”

David Reich, a geneticist at Harvard Medical School and one of the authors of the study, too, points this out in his new book, Who We Are and How We Got Here. Writing in the context of a previous study that he worked on, in which he classified present-day Indians as the outcome of mixtures between ANI and ASI, he said, “The ANI are related to Europeans, central Asians, Near Easterners, and people of the Caucasus, but we made no claim about the location of their homeland or any migrations. The ASI descend from a population not related to any present-day populations outside India. We showed that the ANI and ASI had mixed dramatically in India. The result is that everyone in mainland India today is a mix, albeit in different proportions, of ancestry related to West Eurasians, and… more closely related to diverse East Asian and South Asian populations. No group in India can claim genetic purity.”

Criticism

However, the study has invited criticism from some. ICHR member and guest professor at IIT Gandhinagar, Michel Danino, said that the study is “steeped in circularity”. “It accepts the Indo-European migrations into Europe and into South Asia as a fact, then repeatedly fits the genetic evidence to this ‘fact’. This is faulty methodology…,” he said. He pointed out that “No ancient Harappan DNA has been analysed, which could have provided some secure comparison for contemporary samples in Central Asia and elsewhere.”

Danino also says that the study assumes that South Asia was more or less empty of population in the pre-Harappan era. “It sweeps aside the subcontinent’s Mesolithic and Neolithic populations which undoubtedly have substantial contributions to the South Asian genome. It considers such Mesolithic and Neolithic populations only in the context of Central Asia and Europe! This is one example [among others] of a strong Eurocentric bias in the study,” he says.

Credit: Indian Explain Explained (http://indianexpress.com/article/explained/the-long-walk-did-the-aryans-migrate-into-india-new-genetics-study-adds-to-debate/)

GK: Understanding Rainfall Pattern in IVC (HISTORY)

The Indus Valley Civilisation is one of the earliest known instances of organised urban human settlements. It flourished in the northwestern parts of the Indian subcontinent, in the region around north Rajasthan, Haryana, Punjab, and more prominently in the areas around the Indus river in Pakistan, for about 1,500 years between 3000 and 1500 BC. Its most glorious phase was the 600-700 years between 2600 and 1900 BC, which saw the emergence of some of the most modern and mature townships of that era, like Harappa, Mohenjo-daro, and Rakhigarhi.

The decline and disintegration of the Indus Valley Civilisation are attributed to several reasons — climatic, tectonic, and even social. There are varying degrees of evidence to support these. Most scientists and archaeologists agree that the availability of abundant water was the most crucial enabler for the sustenance of the civilisation in this region, just as it is seen in most other ancient civilisations as well. Presence of prominent buried channels between Fatehabad and Tohana in Haryana, and the concentration of archaeological mounds on its bank suggest the dependence of Indus people on a perennial source of water.

There are plenty of geological and climatic studies that point to good rainfall patterns in that area in those times. There are a few examples of counter-evidence as well, some that show that the civilisation flourished mostly in drier times. A group of geologists, archaeologists and climate scientists from India, United Kingdom and France have recently published fresh evidence in Nature Scientific Report that shows that Indus Valley Civilisation was at its peak in the wettest phase.

These scientists, led by Yama Dixit of Godwin Laboratory for Palaeoclimate Research at the Department of Earth Sciences in Cambridge University, have managed to establish a high resolution chronology of the wet and dry phases in the area between 9000 and 2000 BC, and show that the peak of the civilisation almost coincided with the wet phase when monsoon intensified for about 600 years between 5,000 and 4,400 years from now (about 3000 to 2400 BC). The dispersal of the civilisation also coincides with the onset of the dry phase in the region.

The group relied on the studies of gypsum deposits at the site of a now-dried-up lake near Karsandi village in the Nohar-Bhadra area of northern Rajasthan, which is on the margins of the Thar desert. Such palaeo-lakes — there are many in this area —have been the subject of previous investigations as well, but this is the first time that the scientists have been able to propose a detailed chronology of rainfall variation in those areas having a bearing on the expansion and contraction of Indus urbanism. The Karsandi palaeo-lake is about 120 km northeast of Rakhigarhi, an important Indus settlement that has seen some exciting excavations very recently, and near Kalibangan and Karanpura, also important centres of the Indus civilisation.

Gypsum, chemically calcium sulphate, is one of the common evaporites — the mineral deposits that remain after the evaporation of saline water — found in the palaeo-lakes in these areas. Its chemical analysis gives scientists some good indications about the source and composition of water in these lakes and the environmental condition at the time of precipitation. For example, if the deposit is pure gypsum, it can be an indication of no or very less rainfall in the region. This is because the surrounding areas in the region are all very sandy, and if there was rainfall, the rains would have brought sand to the lake, and the deposits would have a mixture of gypsum and sand. Similarly, pure sand can be indicative of very good rainfall.

The scientists collected samples of different layers of gypsum and studied them in detail. They carried out AMS carbon-dating of tiny ostracod fossils to assess the ages of different layers, and measured the isotopic composition of oxygen and deuterium in gypsum from these layers. Based on their studies, they have been able to propose a specific timeline for rainfall variation in this region. They have inferred that this region, northern part of Rajasthan, was largely dry till about 11,200 years ago, that is until about 9000 BC. But between 9000 and 3000 BC, there was substantial precipitation in the area, making it conducive for human settlements. The scientists say a further intensification of monsoon was witnessed between 3000 and 2400 BC, after which another dry phase is supposed to have begun similar to the modern condition.

This timeline almost coincides with the rise and fall of the Indus civilisation. The evidence from Karsandi lake, therefore, strongly suggests that there were areas that were receiving favourable rainfall in the period leading up to the development of urban centres along the northern part of the Thar desert.“Our findings add to the evidence that climatic reasons could have been one of the main factors behind the sustenance and decline of the great cities of Indus civilisation. Of course, much more work needs to be done in this and many other areas of this region to bolster this evidence,” Saini, the former Director of Geological Survey of India, said. The study has implications for modern society as well, which is witnessing climate change and perceptible variations in precipitation and temperature.

Credit: Indian Express Explained

GK: Understanding Rakhigarhi Excavation Findings (HISTORY)

A 3-season excavation in Haryana’s Rakhigarhi by archaeologists from Deccan College, who worked with Haryana government, ASI, ICHR, and a South Korean team, has unveiled a large burial ground that promises a very detailed anthropological profile of the Harappan people.

The findings

The excavation yielded 53 burials, six of which were unearthed in 2014-15; the remaining in the 2015-16 digging season. The necropolis (a cemetery, especially a large one belonging to an ancient city), dated to between 2,500 BC and 2,000 BC, or the Mature Harappan Period, sprawls under a 1 hectare patch of land that has long been under cultivation by present-day residents of Rakhigarhi. Some of the graves contained full skeletal remains, and have been classified as primary burials; in others, only a few human bones were found along with votive pots (secondary burials); in yet others, only pots were found (symbolic burials that suggest that the person died elsewhere, and was symbolically interred here).

In all, the excavation unearthed at least 46 sets of complete or partial skeletal remains — 41 in primary burials; five in secondary burials. The researchers subcategorised the primary burials into “typical” and “atypical” cases. Typical cases — single bodies buried in supine position (The supine position means lying horizontally with the face and torso facing up, as opposed to the prone position, which is face down)  inside a plain pit — outnumber atypical ones, which have brick-lined graves, multiple bodies, or prone-positioned burials.

Of the 46 sets of skeletal remains, 37 were subjected to anthropological examination and DNA tests. Seventeen were determined to be over 18 years of age (adults); eight were “sub-adults”, that is, younger than 18; and the ages of 12 could not be determined. Two of the sub-adults were children aged between 2 and 5 years. Of the 17 whose sex could be determined, seven were found to be males, and 10 were females.

The tests

The findings were analysed at Deccan College, Pune, and at the DNA lab at the Centre for Cellular and Molecular Biology in Hyderabad. Deccan College has a research collaboration for the Rakhigarhi project with the College of Medicine at Seoul National University, and the DNA tests were conducted at the Hyderabad lab by South Korean scientists. The DNA was extracted using a new technique that involves rupturing the petrous bone, a small bone between the jaw and the ear. Only teeth or jaw bones have so far been considered for extracting DNA.

Dr Dong Hoon Shin, one of the South Korean scientists, posted online that the investigation involved, “1) gross anthropological study (determination of sex and age, identification of any pathological signs in bones, forensic investigation for race determination, etc.); 2) paleoparasitological study (analysis of soil sediments on hipbones, determination of any presence of parasite eggs, drawing of tentative conclusions on parasitic infection of Harappan people); 3) aDNA mitochondrial, Y-chromosomal, autosomal and stable-isotope analyses (obtainment of information on maternal and paternal lineages); 4) first-ever facial reconstruction of approximately 4,500-year-old Harappan person (based on DNA and forensic data…).”

The significance

This isn’t the first time that such burials have been found at a Harappan site — the most signficant necropolis was found in Harappa itself; burial grounds have also been discovered in Lothal (Gujarat); Kalibangan (Rajasthan); Farmana (Haryana), Sanauli (UP), and during a previous Archaeological Survey of India excavation in Rakhigarhi in 1997-2000.

It is important to note, however, that the numbers of known Harappan sites are over 2,000, and funerary findings are, therefore, still sparse. While Harappan studies have focused primarily on urban design, crafts and trade, funeral customs say a lot about a community, what its people value, its social heirarchy, gender relations, and how it treats its children. Forensic-anthropolgical studies of remains can reveal much about what a people ate, their longevity, and why and how they died. Studies of funeral customs can reveal links between peoples across space and time.

There are five big known centres of the Harappan civilisation — three in Pakistan (Harappa and Ganweriwala in Punjab, and Mohenjo Daro in Sindh), and two in India (Dholavira and Rakhigarhi). While the study authors are careful to underline that “the Harappan Civilization’s normative form or forms of body disposal remains unclear to us, (and) we have to allow for the possibility that diverse groups… had distinctive mortuary customs”, in Rakhigarhi, a distinctive practice was “the burial of the body without any process of reduction”.

Peculiar features

The paper has noted pit burials with multiple bodies, and prone (face down) burials as significant departures from other Harappan necropolises. Most burials pits, however, had only set of remains, and the body was fully extended in the supine (face up) position, with the head to the north. Some graves had pots in them, others had none.

In some graves, some votive pots had animal bones, which may have been from meat placed with the body as an offering to the dead. In secondary burials — pots containing human bones — the remains bore no signs of charring, thus ruling out cremation as a practice.

One atypical burial contained five sets of remains in one pit. According to the study, all were buried at the same time — the two skeletons found in the pit, that is primary burials, were excellently preserved, and appeared to be male. The others were secondary burials, and contained human bones in pots. This multiple-individual grave had a higher number of “grave goods” than in any other burial pit found at Rakhigarhi.

What the finds indicate

The burial structures and grave goods of the Rakhigarhi necropolis were “determined to be generally humble in nature”, says the study, with their differences being “possibly reflective of ritual status and/or the dynamic situation prevailing at the time of the individual’s death”. Brick-lined burials (as opposed to plain pits) were among the most elaborately constructed graves, and possibly implied a high social or ritual status.

Significantly, every individual found in a brick-lined pit was determined to be female, leading the study authors to ask whether these women played a special role in the community. Brick-lined graves also included more votive pots than did typical interments; however, women in typical burials got fewer votive pots than men, leading the study to ask if there were “discriminatory” attitudes toward women in general.

Prone-position bodies, a rarity in archaelogical finds, are usually held to be those that the community did not like. However, in Rakhigarhi, these individuals seem to have got elaborate burials with numerous grave goods. Two burials had been done on a bed of pottery, which may be indicative of high social status.

Combined with other finds, including a goldsmith’s workshop, a complex of mud-brick structures, and the usual Harappan antiquities — potsherds, terracotta, agate and steatite beads, stone and copper artefacts — the necropolis confirms the earlier belief that there was a sizeable community at Rakhigarhi.

Credit: Indian Express Explained