You might assume only geneticists and serious nerds would be interested in Y-chromosome DNA haplogroups, which are gene clusters showing descent from a common male ancestor. Yet, one such haplogroup, known as R1a, has become integral to the fierce debate about India’s ancient history. An individual who died some 4,500 years ago in Rakhigarhi in present day Haryana is entangled in the R1a controversy. Political pressure delayed an eagerly awaited study of that man’s genetic make-up, but it finally seems ready for print, and its findings were summarised in India Today by the magazine’s Managing Editor Kai Friese. Friese’s article was less about what the researchers found than what they didn’t find. What they didn’t find was the marker R1a.

Had that marker been detected, Hindutvavadis would have been ecstatic. They would have felt vindicated in their belief that the Indus Valley people were no different from the Vedic people; that residents of ancient towns like Harappa, Mohenjo-daro, Dholavira, and Rakhigarhi worshipped Hindu gods; and that India’s earliest urban culture ought to be called the Indus-Saraswati civilisation. The alternative, which the Hindu Right fights tooth and nail despite decades of accumulated evidence, is that the Vedas were composed long after the peak of the Indus Valley civilisation, by a people who migrated into the sub-continent at most 4,000 years ago, whose language descended from one first spoken in the grasslands of Eastern Europe and Central Asia.

The story of India

For those who follow evidence rather than ideology, the story of how India was populated is now fairly clear. It will continue to be refined and fleshed out, but here is the gist of it. Around 70,000 years ago, bands of anatomically modern humans began migrating out of Africa. They eventually occupied virtually every inhabitable place on earth, arriving in India at least 50,000 years ago.

Around 10,000 years ago, a second massive migration was triggered by the discovery of agriculture and a consequent population explosion. In a region of West Asia known as the fertile crescent, humans learned to grow wheat and barley and domesticated cattle, goats, sheep and pigs. They took this knowledge west into Europe and east through Iran to South Asia. Agriculture was invented independently a little later in China and later still in Mexico. Rice cultivation came to India from the east, but the associated migration did not have as strong an impact on India’s population as the one from Iran.

After the coming of agriculture, the economy of North India grew steadily, till it was large enough to support towns like Harappa and Dholavira. The people of these towns, and of the Indus Valley civilisation more broadly, were a mix of two groups: indigenous hunter gatherers descended from the first waves of migrants out of Africa, and farmers who had arrived much more recently. Since individuals would have carried genes from the two groups in different proportions, the population must have looked diverse.

Two of four human skeletons dating back to the 5,000-year-old Harappan era, which have been recovered, are pictured at a burial mound at Rakhigarhi village in Hisar on March 11, 2015. Four complete human skeletons – two men, one woman and a child – were found. (Photo credit: Manoh Dhaka/AFP)
Two of four human skeletons dating back to the 5,000-year-old Harappan era, which have been recovered, are pictured at a burial mound at Rakhigarhi village in Hisar on March 11, 2015. Four complete human skeletons – two men, one woman and a child – were found. (Photo credit: Manoh Dhaka/AFP)

Out of Steppe

Around 6,000 years ago, a new migration began from the grasslands north of the Black Sea, spurred by the invention of horse riding. Horses had been hunted by Stone Age inhabitants of Europe and Asia for millennia, but their domestication and use as steeds was first achieved by semi-nomadic pastoral communities on the Eurasian steppe. The horse people of the grasslands became formidable warriors, especially after they learned to hitch spoke-wheeled chariots to their horses.

Moving outwards from the steppe, they spread what would become their biggest contribution to the modern world: their language. It was the ancestor of Greek, Latin, Old Iranian, Sanskrit, and all their daughter tongues, now known as the Indo-European language family. Today, over 40% of the world’s people speak a mother tongue descended from the language of those nomads of the steppe.

The incursion of the horse riders into India left a genetic imprint, with one very peculiar quality: The steppe genes were transmitted primarily by males. There is a form of DNA, called mitochondrial DNA, which is passed from mother to progeny. The mitochondrial DNA of modern Indians shows little steppe influence, meaning that females from among the pastoral migrants did not mate with or marry males from communities already settled within India in significant numbers. The men, on the other hand, left their mark on Indian Y chromosomes, the most famous being the R1a haplotype.

I hope it is clear now why the Rakhigarhi study was politically fraught. The presence of R1a would have undercut the idea that a migration originating in the steppes brought Sanskrit to India at a time when the Indus Valley civilisation was in decline. I am not surprised no R1a was found. In a previous column I set down some of the evidence showing that Sanskrit and the Vedic religion have their origins outside the subcontinent. Recent genetic data only bolsters what we know from other disciplines like archaeology, linguistics and comparative religion.

The man from Rakhigarhi turns out to have been genetically proximate to members of the Irula community, an Adivasi group living in Tamil Nadu and Kerala, whose traditional occupation is catching rats and snakes. This connection strengthens the common hypothesis that Indus Valley populations spoke a Dravidian language, and that incursions of the horse-people from the north-west created waves of migration southward. As a result of these upheavals, a large percentage of today’s North Indians carries “steppe genes”, and virtually all Indians, Adivasis included, carry “farmer genes”. (Researchers have come up with terms like ANI, Ancestral North Indian, and ASI, Ancestral South Indian, to describe different hypothetical populations. I have not employed the terms because I find them misleading. The ANI population, for instance, had little to do with North India.)

The Hindutva view

A few intellectuals from the Hindu Right have attempted to reconcile Hindutva history with genetic, archaeological and linguistic evidence. They make two arguments against the story of migration I have sketched. They attack it as racist, and claim we only have proof of migrations but no proof of the direction of those migrations. In the Hindutva view, Indian horse riders migrated to the steppes, taking with them R1a and the mother of Indo-European languages, not the other way round.

Sanjeev Sanyal, Principal Economic Advisor to the Ministry of Finance, who has written Hindutva-friendly books of popular history, expressed these views in a Twitter thread, along with a couple of other tendentious claims, after a major study of the genetics of south and central Asia reinforced the established view of migration into India. Sanyal uploaded a photograph of a prehistoric depiction of a horse, with the comment, “The earliest evidence of horses in Asia are not from Central Asia but from the middle of Arabia. 10,000 year old cave art show horses, much earlier than steppes. So, even the horse was a ‘southern’ animal”. This is a strawman argument. Wild horses, like the ones painted in France’s Lascaux caves over 15,000 years ago, roamed Asia and Europe for millions of years before modern humans appeared. The innovation of the steppe people was to domesticate them, ride them, and hitch them to spoke-wheeled chariots. No remains of such vehicles have been found at mature Indus Valley sites, though they play a major role in Vedic mythology.

Sanyal’s second argument was that R1a spread from east to west, because, “India is the only place where its various cousins like R2, R1b are found.” I’m not a geneticist any more than he is, but it appears his assertion about R1b is untrue: it is barely present in India. That factual error aside, the central problem with the east-to-west thesis is that, had Indians carried R1a west and north, other bits of India-related DNA would have shown up in Western populations, but that did not happen. To suggest east-to-west migration given this fact is like claiming you could mix three colours thoroughly and daub them onto a plain piece of paper in such a way that only one of the three colours was deposited on the paper’s surface.

Product of imperialism

The most persistent argument against the steppe migration thesis is that it is a product of racist, imperialist thought. In Sanyal’s words, “Once you remove the racist assumption of a superior white conqueror from the North, the available data is all quite consistent.” While it is true that the “conquerors” were almost certainly paler skinned than most residents of Indus Valley cities, we do not know what their precise complexion was, so to call them “white” is misleading. Secondly, settled agricultural societies were more advanced than the steppe pastoralists in a number of ways. The farmers built cities, evolved systems of writing and developed complex trade routes, while the herders were illiterate nomads. The horse people were indubitably superior in one respect only: they were better at war. Of Sanyal’s three categories, “white”, “superior” and “from the north”, only the last accurately renders the steppe migration thesis. His assertion about racism, like the one about horses, is a strawman.

It is true that the study of the spread of Indo-European languages has been utilised in the past by racists. The Nazis believed the original speakers of Proto-Indo-European were pale, blonde, North Europeans who disseminated their language while conquering inferior races. However, Nazi ideas about the geographical origin and ethnicity of the “Aryans” were discredited decades ago.

The more we learn about the past the crazier white supremacy sounds. It seems likely, for example, that Stone Age inhabitants of places like Britain and Spain were dark skinned. They grew pale relatively recently, thanks substantially to a genetic mutation probably brought to Western Europe by farmers from Asia, and first identified by scientists studying the pigmentation of zebrafish.

There has been no outcry in the UK against the idea of dark-skinned ancestors. The French have organised no marches protesting the notion that agriculture was invented in Asia. Italians are perfectly content that the roots of their language lie outside West Europe. Swedes happily acknowledge that modern humans arose in Africa. These theories are grounded in hard data, neutrally interpreted, rather than racism. It is the opposition to evidence-backed hypotheses that is biased. Chauvinism combined with a twisted inferiority complex drives assertions that we always worshipped these gods, always spoke this language, always looked like this, and were always right here.

Corrections and clarifications: An earlier version of this article inexactly stated that mitochondrial DNA is passed on from mother to daughter. It is passed down the generations by mothers through daughters, but in any given generation it is inherited by both sons and daughters. This has been corrected.