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This story is centred around the discovery of a skeleton belonging to a woman who lived around four and a half to five thousands years ago in the ancient city of Rakhigarhi in Haryana. Ever since the discovery of her skeleton and the subsequent DNA analysis conducted on it, newspapers columns, social media platforms and public forums have been abuzz with activity. The reason for this flurry of activity are three contentious points:
- One, that since the Harappan DNA did not have any traces of Iranian farmers, the Vedic society was also developed by descendants of the Harappans alone without intervention from the West.
- Second, that it was Harappans who migrated out to West Asia, rather than the other way round, because some ancient individuals with the same ancestry profile as the Rakhigarhi woman, were found in Iran and Turkmenistan,
- And lastly, the absence of Central Asian or Steppe pastoralist genes in Harappan DNA meant the Indo-European languages did not come from the West
Before we get into these issues, let’s talk about how this discovery process took place, because there are some interesting points that will add more context.
The Harappan or Indus Valley civilization has always baffled archaeologists right from the time it was discovered. The earliest archaeologists who visited the first sites of Harappa and Mohenjo Daro, estimated the age of these ancient cities as not older than 250 years. But quite soon, comparisons with ruins of the Mesopotamian civilization put the age of these sites in the range of a few thousand years. From the 1920s when Harappa and Mohenjo Daro were excavated, we have come a long way in terms of our understanding of this civilization. What we now believe, based on scientific research and laboratory studies is that there were at least 3 phases of the Harappan civilization – the early, mature and late phases, and these phases spanned almost two millennia of time, between 3300 BCE and 1300 BCE. These date ranges keep getting adjusted as newer discoveries take place, but it is an average approximation that most historians agree with. There are also pre-Harappan sites that developed as early as 7000 years BCE and there is evidence of agriculture as well as goat-herding at these sites, suggesting that early Iranian herders and farmers probably mixed with the local populations.
The Harappan civilization developed during the urban phase of South Asian history. It is symbolized by the presence of large buildings, wide roads, drainage systems, granaries, water tanks, terracotta artefacts like seals, bangles, and toys, and importantly a standardised system for measuring weights. There is also the presence of burials at most sites, and this proves that the early South Asians were burying their dead, and they were doing this in a very civilized manner, where in every grave had some burial or grave goods. These would typically be earthenware like pots, dishes, bowls, and at times ornaments or jewellery made of beadstones. In some graves there is also evidence of food offerings in the form of meat, most likely goat, sheep and cattle meat. The Harappans followed a convention for these burials such as all the bodies being placed in a north-south direction, with the head being placed at the northern end, signifying the same belief system that Hindus continue to follow in India even today. The grave goods were also placed at the northern end of the burial sites. These are some signs of social continuity. But the hardcore evidence for ancestry is coming from genetic analysis and that’s where the Rakhigarhi woman becomes quite important.
Rakhigarhi is a small village in the Hisar district of Haryana that was identified as the location of a large Harappan site in the 1970s, although excavations took place only in 1997, and over three years, these excavations revealed seven mounds or elevated landforms around this village, under which the ancient city was buried. The estimates of the size of the city range between 80 hectares to 100 hectares though there are some reports that suggest it could be even as large as 300 hectares. Even the modest estimate of 80 hectares makes this site comparable in size to Harappa and Mohenjo Daro. The first excavations revealed among other Harappan features, a large cemetery in the northern part of the site. Dr. Amarendra Nath who was leading the 90s excavations, was able to expose 11 burials and 8 complete skeletons. Unfortunately for him, the human genome hadn’t yet been fully mapped and published, which happened only in the year 2000, and since then archaeology, like other sciences, has tried to leverage the genome mapping to validate assumptions made until now based purely on historical and archaeological evidences. The next set of excavations took place between 2013-2016, and this was led by Dr. Vasant Shinde, the former Vice Chancellor of the Deccan College in Pune, and he was joined by a team of forensic experts from South Korea, who specialize in forensic analysis of archaeological finds.
Dr. Shinde and his team chose to focus on the cemetery spread out over the seventh mound in Rakhigarhi, and soon enough they exposed 53 graves with 46 intact skeletons. This was a big discovery, and it raised hopes of finally extracting ancient Indian DNA. The Indian archaeological sites, very rarely provide usable DNA samples, and this is because of the nature of soil composition, high levels of humidity and heat, and also soil erosion. Therefore, with great care, the Rakhigarhi team attempted to extract DNA from the ancient skeletons. There were, in all 61 specimen, which included the 46 skeletons but also 15 individual skeletal remains. Dr. David Reich, a genetic scientist in Harvard University, received these samples and conducted DNA analysis on them, the results of which have been published in the latest research paper.
What Dr. Reich and his colleagues at Haravard discovered, was that out of all the 61 Rakhigarhi specimens, only one, belonging to a woman, had promising genetic material, and they labelled this specimen I6113. From her DNA they were able to trace two lines of ancestry, one belonging to ancient Iranians and the other to Andamanese Hunter Gatherers or ancient South Indians. This ancestry profile was unique in the South Asian context because it did not match any profile from ancient to modern South Asians. This was a sign that the Rakhigarhi woman had to be one of the most ancient ancestors of South Asians, and whose DNA had not yet seen the mixtures that would take place later on. But she seemed to have some cousins who lived far away from the Harappan civilization sites. Let’s see who were these ancient cousins?
About a year before this research was published, another paper had come out in March 2018 from one of the co-authors of the Rakhigarhi paper, which talked of a newly discovered Indus Periphery group that was formed from ancient Iranian and South Asian populations that the research claimed to be the single most important source of South Asian ancestry. This research was based on genomic analysis of 362 individuals across Iran, Turkmenistan, Uzbekistan, Tajikistan, Kazakhistan and South Asia. Amongst the 362 odd individuals, there were some outliers, roughly 3 individuals who were found in the sites of Gonur in Turkmenistan and Shahr-i-Sokta in eastern Iran. Their DNA was composed of very early Iranian agriculturists and South Asian hunter gatherers and this profile matched closely with that of later specimen from the Swat valley in Pakistan who had lived between 1200-800 years BCE. Therefore, it was clear that these outliers were early ancestors of South Asians. They were named the Indus Periphery group since the sites where they were found showed cultural contact with Indus Valley or Harappan sites. From this paper, the main conclusion drawn was that the spread of Indo-European languages happened with this kind of southward movement of Iranian populations into South Asia. However, the paper also stated that without DNA of individuals buried in IVC sites, it was difficult to say that the ancestry profile of these outliers was common across the entire Indus Valley Civilization. It was still 2018, and this would change, as the Rakhigarhi woman’s DNA would be analysed and also that of 8 other outlier individuals who were found in the same sites of Gonur and Shahr-i-Sokta.
Coming back to the problem of this unique ancestry, now in 2019, it looked plausible that the Rakhigari woman and the 11 outliers were part of the same ancestral profile, and they were together called the IVC Cline, cline standing for genetic variant. The IVC cline raised another important question. Were these South Asians who had migrated to Iran and Central Asia, or were these Iranians or Central Asians who had migrated to South Asia. The higher composition of Iranian ancestry would perhaps logically suggest that it was Iranians who had moved southwards and mixed with South Asians, but the researchers of the September 2019 paper think otherwise. They believe that these were South Asians who had migrated northwards, since their discovery sites had shown cultural contact with the Indus Valley sites, and also because their ancestry profile was rare amongst other individuals from these sites. They were 11 amongst 44 other specimen whose DNA had been analysed, which made them 25% of the specimens. Now, is 25% rare, is hard to say. The other reason why these researchers believe that this was an out-of-South Asia migration, is that the Rakhigarhi woman’s ancestry profile suggests there were Harappan people with this profile living in Harappan cities, so her profile should have had traces of Central Asian populations had she been a migrant herself from those regions. Since it does not have any Central Asian traces, she could not have migrated from there. The current controversy raging over this out-of-south Asia theory is difficult to resolve until we find some more ancient DNA from Harappan sites.
Lastly comes the question of languages. The prevailing assumption has been that the spread of Indo-European languages took place with the migration of Iranian farming populations who brought with them advanced knowledge of agriculture. The latest report does not reveal the DNA of later Iranian agriculturists in the Rakhigarhi woman nor in the 11 other individuals. This has led some people to believe that South Asians developed their knowledge of agriculture indigenously without intervention from outside cultures. But it may be too soon to say that, because the 2019 paper itself states that Indo-European languages may have spread to South Asia with migrating Central Asian populations in the 1st half of the 1st millennium BCE as Stepp populations interacted with the Indus Periphery populations. The 2018 paper also said that Indo-European languages dispersed in the South Asian region during the 2nd Millennium BCE as Steppe populations mixed with the Indus Periphery populations. The reason both papers say this is also owing to the fact that modern day Indians have a Central Asian gene variant or Haplogroup known as R1a, which occurs on an average in 30% of the North Indian population, with as high as 70% frequency in some castes that have maintained endogamous or within the caste marriages over centuries. This genetic trace cannot be explained away by the Rakhigarhi DNA. Therefore, it is almost certain that somewhere around the time the Harappan civilization dwindled away, there was intermingling of Central Asian tribes and late Harappan people who may have carried the ancestry profile of the Rakhigarhi woman. This could have produced the next phase of Indian civilization which we refer to as the Vedic period. Some other evidences that support this theory, apart from genetic science, are historical in nature. The Vedic hymns often refer to horses and chariots when they talk about the Vedic deities like Indra, Varun, the Ashwins. It is an established fact that the earliest wheeled chariots were built by the Central Asians, and the development of spoked wheels also took place in this region. Therefore, it gives us more reason to believe that the Central Asians may have brought with them the knowledge of domesticating horses and building chariots, thereby also spreading their genetic material in post-Harappan South Asia.
So, until we find more genetic evidence in Harappan sites, it would be incorrect to assume the absence of Central Asian influence in the post-Harappan period based on the DNA analysis of a single individual from a Harappan site. But controversies are not always based on facts, but on ideology and faith which can blind people on either side of the argument into trying to prove their pre-determined conclusions by tweaking scientific discoveries as well. I hope we all learn from past mistakes, and not let this fantastic research turn into a tool for divisive politics or racial disharmony in these cosmopolitan times. Somewhere in the paper, I read the researchers also refer to Harappa as a cosmopolitan society, and that gives us even more reason to not throw away such a beautiful legacy.
Shinde et al., An Ancient Harappan Genome Lacks Ancestry from Steppe Pastoralists or Iranian Farmers,
Cell (2019), https://doi.org/10.1016/j.cell.2019.08.048
RAKHIGARHI AND THE HARAPPAN CIVILIZATION: RECENT WORK AND NEWCHALLENGES
Author(s): VASANT SHINDE, ADAM GREEN, NAREÑDER PARMAR and P.D. SABLE
The Genomic Formation of South and Central Asia, (Authors: Vagheesh M. Narasimhan1, Nick Patterson2,3)
Images: Shinde et al., An Ancient Harappan Genome Lacks Ancestry from Steppe Pastoralists or Iranian Farmers,
Cell (2019), https://doi.org/10.1016/j.cell.2019.08.048