The Aryan Invasion Theory Is Finally Proven Right: Science - 1, Hindu Right-Wing - 0

For years, a needless ideological battle has been fought in India. The root of the debate is a seemingly irrelevant question - Did the ancient Indian "Vedic" civilisation originate in India or did it come to India from outside?

To most rational people, this would seem to be a non-issue. Does it even matter? Indian culture today is what it is. A study of its origins and roots is interesting, but it shouldn't change the way Indians look at themselves or their cultural practices.

However, to one particular group of people, the origins of Indian culture, equated by them to "Vedic" culture, is of crucial ideological importance. The people and organisations loosely affiliated under the generic "Hindutva" umbrella are very keen to establish that Vedic culture originated in India and was not imported into the South Asian region by an external group of people. It seems to be a point of pseudo-nationalistic pride with them and nothing more. Even to devout Hindus who believe in Vedic scriptures, myths and rituals, it should not matter a whit whether Vedic culture was indigenous to India or not. As I said before, Indian culture is what it is. There is no need to make its exact origin a point of pride. And yet that's the way the Hindu right-wing has chosen to play it.

A seal from the Indus Valley Civilisation depicting a strange-looking animal. There is speculation that the civilisation did not know of the horse, which was introduced into the region by invaders from Central Asia.

When I was growing up, I learnt in my history books about the Indus Valley Civilisation that existed from about 3300 BCE to 1300 BCE, with its mature period between 2600 BCE and 1600 BCE. The culture of this civilisation was suggested to be Dravidian. I also learnt about the 'Aryan Invasion Theory', which held that a different race of people from Central Asia or the Middle East invaded India, destroyed the Indus Valley Civilisation, drove the Dravidians to the South of the country, and settled in the North. They brought with them a different culture, including a different set of gods and religious rituals (the Vedic culture). Over time, there was some cultural and genetic cross-pollination between the two groups, but the predominant genetic/racial and cultural divide of Aryan versus Dravidian remains in India today as North Indian versus South Indian.

That's what I learnt at school, and so did the rest of my generation. In addition to what was taught in textbooks, I learnt from observing politics that some South Indian politicians (notably belonging to the "Dravidian" parties of Tamil Nadu) accused "upper-caste" people even in South India of being Aryans. So the popular discourse seemed to uneasily entertain (if not fully accept) the idea that India consisted of two races of people - the Aryans and the Dravidians. The Aryans were typically North Indians and "upper-caste" people; the Dravidians were typically South Indians and "lower-caste" people.

Somewhere along the way, this set of hypotheses began to acquire ideological overtones. People belonging to the Hindu revivalist movement intensely disliked it. To them, this seemed at once to have two implications:

1. It divided Hindus into two (or four) groups - North vs South, and upper-caste vs lower-caste. Viewed from their ideological angle which saw Muslims and Christians as enemies of the Hindus, such internal schisms within Hinduism were an unacceptable weakness.

2. Their own perception, perhaps born of cultural insecurity, was that it called into question the very legitimacy of the Hindu Vedic tradition, by suggesting that it may have come to the country from outside and was therefore not worthy of respect as a genuinely original civilisation.

For these two reasons, Hindu revivalist groups such as the Hindu Mahasabha (now defunct) and later the Rashtriya Swayamsevak Sangh (RSS) and its sister organisations, have worked very hard to disparage the Aryan Invasion Theory. One could understand a Hindu revivalist movement working to eliminate regional, linguistic and caste differences among Hindus through a positive appeal to unifying ideas, but the approach they took was entirely different. It was through the more expedient means of attempting to disparage the Aryan Invasion Theory by imputing anti-national motives to historians.

That has been the background to the debate so far, and the ideological lines have been drawn. Western Indologists like Max Mueller, colonial-era British historians such as Mortimer Wheeler and Indian ones like Romila Thapar are on one side of this debate. Intellectuals (to use a term that errs on the side of respect) such as Michel Danino, Koenraad Elst, David Frawley and Rajiv Malhotra are on the opposite side. The hypothesis favoured by the latter group is the 'Out of India Theory' which postulates that far from India being the recipient of an Aryan migration from Central Asia, it was India that was the original home of the Aryans, who then migrated outwards.

Under the onslaught of the right-wing reaction, the proponents of the Aryan Invasion Theory have back-pedalled a bit, and conceded that "invasion" was probably too strong a term. They have settled for a milder term - "migration". It's the Aryan Migration Theory that is a little more respectable nowadays. However, even that is disputed by the Hindu right.

While this debate has been rancorous, a lot of it has been based on conjecture and circumstantial evidence. But in recent times, genetic research has begun to provide clearer answers.

In 2013, a paper by Priya Moorjani et al made a number of important points based on genetic evidence, and I have blogged about that here. To recapitulate,

1. Virtually all groups in India, including those considered to be isolated, have experienced an admixture of two distinct racial groups in the past. There are no "pure" groups today.

2. This admixture took place over a period of time, between 4200 years ago and 1900 years ago.

3. The paper calls these two original racial groups ANI and ASI (Ancestral North Indian and Ancestral South Indian). The ANI group has links to Central Asia, the Middle East and Europe, although the paper takes care to explain that it has no immediate links to Eurasians and hence may have separated from the Eurasian group 12,500 years ago. The ASI group does not have links to any group outside of India, with the closest group being in the Andamans. Hence the ASI group is probably indigenous to India.

4. Present-day Indo-European groups in India (i.e., North Indians) have a higher proportion of ANI genes than ASI. Present-day Dravidian groups (i.e., South Indians) have a higher proportion of ASI genes than ANI.

So far, the data seems consistent with the Aryan Invasion/Migration Theory in that the ASI group indigenous to India seems to correspond to the Dravidians, and the ANI group with links to Central Asia seems to correspond to the Aryans. However, it isn't that straightforward.

5. The dates of admixture are more recent among Indo-European groups than among Dravidian groups. A plausible theory is that Indo-European groups received a second infusion of ANI, making the effective date of the admixture appear more recent. This is backed up by the fact that many North Indian genomes have long stretches of ANI interspersed with stretches that are a mosaic of ANI and ASI, pointing to a more recent admixture on top of an earlier one.

6. "Upper" and "middle" caste people's genomes show multiple waves of admixture compared to "lower" caste genomes. The paper does not offer an explanation for this, but my theory is that lower caste people were less mobile and had fewer opportunities to interact with outside groups, perhaps as a result of social restrictions.

On a matter that can be seen to have a major bearing on our understanding of caste, the paper makes a further surprising claim based on the genetic evidence.

7. An abrupt shift to endogamy (the opposite of cross-breeding) occurred around 1900 years ago. Some groups stopped receiving gene flows from neighbouring groups 3,000 years ago.

A more recent paper by 16 researchers led by Martin Richards is consistent with the Moorjani paper, and provides much more emphatic evidence.

Its conclusions are explosive. To cut a long story short, the genetic evidence suggests that the Aryan Invasion Theory is probably on the money. The Out of India Theory stands discredited. What's more, it really was an invasion and not a peaceful migration. Read this commentary in The Hindu which explains the conclusions of the paper in layman's terms.

The research for the first time analyses patrilineal DNA or Y-DNA, whereas previous studies had focused on matrilineal DNA or mtDNA. Previous studies had not detected any genetic infusion into India around the time of the Indus Valley Civilisation, but the newest one does. What's more, the dating of this infusion (around 2000 BCE) matches the collapse of the Indus Valley Civilisation to an astonishing degree.

Let's think about this for a moment. No infusion of matrilineal DNA occurred during the 2000 BCE period, but there was an infusion of patrilineal DNA at that time. In other words, a large group consisting almost exclusively of men entered India at that time. What's the probability that this was an army as opposed to a nomadic community of men, women and children? I'd have to say the evidence very strongly suggests an armed invasion.

Let's think further about the remarkable coincidence that the Indus Valley Civilisation should have collapsed at about the same time that a large group of men (that we have to admit was probably an army) entered the region. What's the probability that these were unrelated events? I'd have to say the evidence strongly suggests a cause-and-effect relationship. An invading army caused the downfall of the Indus Valley Civilisation.

The commentary article in The Hindu is however not bold enough to join these dots as I have above. It echoes the researchers' own circumspection by continuing to talk about a "migration" rather than an "invasion".

To my mind, it's all over but the shouting. The genetic evidence very clearly and strongly suggests an invasion of India by men from Central Asia. The Aryan Invasion Theory was therefore on the money. The ideology of the Hindu right-wing, that Aryan (or "Vedic") culture originated in India, and that all Indians share a single and indigenous genetic heritage, lies in tatters.

None of this should matter to regular Indians, who will probably shrug and carry on with their lives, absolutely untouched by what the evidence says about their past. But to the Hindu right wing, which has made this debate such a point of pride, the latest evidence is devastatingly bad news.

It couldn't happen to a nicer bunch of people.