Ancestral Echoes in Indian Genes – Delhi Science Forum

This article is in two parts and meant to expose the fraudulent claims of the Hindutva lobby who have been arguing that new genetic evidence substantiates their thesis of Harappan civilisation being Vedic. In the first part, we examine the genetic methods being used to unravel the past. In the next section we will take up Colin Renfre’s thesis about the origin of Indo-Europeans and its use by the revanchist pseudo scholars such as Rajaram. We will also examine the state of current genetic data and what conclusions that can be drawn on the basis of such data.

ALREADY infamous for his fraudulent attempts to manufacture a horse seal in Harappa, N.S. Rajaram has recently claimed “…genetic studies showed that the presence of any genetic input from Eurasia or Europe in the Indian population was negligible to non-existent. Further, this insignificant imprint was the same in North and South India which flies in the face of the Aryan-Dravidian division” (N.S. Rajaram, Looking Beyond the Aryan Invasion, Open Page, The Hindu, December 19, 2000). This claim has been made not only by Rajaram, but also other revanchist “scholars” — David Frawley, Subhash Kak, Dinesh Maheshwari, etc. It is now being repeated by K S Sudarshan, the RSS Supremo to “prove” the age-old RSS thesis that only Hindus are indigenous to the country, while other religions are foreign. The important point to note here is that no sources are quoted regarding these so-called studies.

What is the truth in the claims that are being made regarding genetic studies of the Indian people? The two major studies in this area — one led by Partha Majumder of Indian Statistical Institute, Calcutta and the other by Madhav Gadgil of Indian Institute of Science Bangalore — have come to completely different conclusions. Majumder in his paper on “People of India: Biological Diversity and Difficulties”, in Evolutionary Anthropology, 1998, says “…… the populations of Southern India stand apart genetically from the populations of North, West, East and Central India”. In a more recent paper in Majumder and his co-authors state ” ..this finding is indicative of a higher Caucasoid admixture in northern Indian populations”, Current Science, November 2000. Gadgil and his co-authors in his article “Peopling of India”, in the Human Heritage 1997, Edited by Balasubramanian and N. Appaji Rao have gone further and suggested that genetic data supports the proposition of a major migration of Indo-European Speakers about 2000 BCE (Before Current Epoch as the preferred usage rather than Before Christ or BC). So why are these revanchist writers talking about genetic data having proved conclusively their case of no invasions from outside?

To understand this, we have to understand not DNA studies and history, but the political compulsions of the RSS Project. This effectively is to disenfranchise the minorities in this country – the Muslims and the Christians – and through this build a state that will be led by the dominant groups within Hindu society. The task therefore does not stop only with marginalizing minorities – it must proceed to marginalize all groups who do not subscribe to the past greatness of Hindu Society and rebuilding the same, albeit with minor concessions to “lower” backward castes, dalits and tribals. For creating this monolithic Hindu future, there is a need to crate an appropriate past. And if the past – in terms of archaeological, genetic or other data does not substantiate their version, so much the worse for the past. It can always be “created” by pliant scholars or not so respectable ones such as Rajaram.

As genetic studies for analysing the history – particularly for periods where the written records are few – are comparatively new, these “new age” revanchist scholars think that they can get away with claims that are either exaggerated or clearly fraudulent. As the Babri Masjid case has shown, with repeated assertions, history can be subverted at least in the popular mind. The sheer newness of genetic studies can provide an authority that other textual analysis may lack. Therefore this continuous and shrill repetitions of what these genetic studies purportedly show.

How does genetics help in historical analysis? The genetic code in living beings is “information” that the cells use to manufacture amino acids; amino acids are central to the functioning of the cells and therefore the genetic code is really the code of life.

How is the genetic code constructed? Any computer code – any statement or a number within the computer – is an arrangement of zero’s and ones. This is the binary code. The genetic code is also similarly constructed. There are four bases – Adenine, Cytosine, Guanine, and Thymine – generally referred by the alphabets A, C, G and T. Each of these bases pair up with another to form a rung. A DNA double helix, if is untangled would look like a stepladder with each rung composed of such pairs. The “up-rights” of this ladder are composed of a sugar molecule called de-oxyribose. The pairing of the bases is always with A pairing with T and C with G. A DNA genetic code of the cell nucleus is thus a series of such pairs – letters of the genetics as given below:

How many of these letters do we carry? Human beings have 3 billion such letters in their genetic code and the basis of unravelling this entire code is the Human Genome Project. Human beings are highly homogenous in their genetic make up: a group of 55 apes in Africa show more genetic variations than the entire human population of 5 billion! They are 99.9% identical. But in a genome of 3 billion letters, even a tenth of a percent difference translates into three million differences in spellings.

Till 80’s, the study of ancient history was confined to archaeological studies – the spade was the most useful tool. However using the pattern of DNA in the people today, we are today able to address certain historical questions in a different way.

There are two types of DNA studies. The studies of Luca Cavelli-Sforza and others have been looking at genetic frequencies of the DNA in the nucleus: the cell DNA. Alan Wilson introduced mitochondrial DNA studies. Cavelli-Sforza’s gene frequency studies examine how frequently a particular gene – a genetic marker — turns up in a population. He reasoned that populations would show smooth changes in gene frequencies based on the migration patterns of the people. The other method focuses not on the DNA in the cell nucleus but in the Mitochondria. Mitochondrial structures convert sugar and oxygen in the cell liberating energy that runs the cell. They are thought to be ancient bacteria that took up residence in the cell, and as a consequence carry their own DNA. The important property of mitochondrial DNA is that they are inherited solely through the mother and therefore we can trace back generations without worrying about mixing of paternal and maternal genes. They also are much smaller and mutate faster making them excellent biological clocks.

The advantage of DNA frequency and mitochondrial DNA, (mtDNA) studies is that they provide independent tools of analysis. Therefore, if both sets of analysis reach similar conclusions, then it provides strong corroborative evidence of the result. It is these tools that have established the out-of-Africa hypothesis that modern homo sapiens emerged in Africa about 150,000 years ago and first left the continent about 100,000 years back. Alan Wilson’s pioneering study refined by others have been confirmed by changes in the Y Chromosome giving roughly similar order of dates for the male and female ancestors of the current human population and have conclusively shown that the cradle of humanity is Africa.

DNA analysis has also exploded the myth regarding races. The genetic variations in the human population within a group account for 85% of all variations; only 9% of all variations are due to different continents while 6% variations are due to differences between groups. The gene for skin colour – the primary difference between races – is an independent variation from that in any other known gene. Skin colour and race are indeed skin deep.

When did the various groups emerge from Africa? The current genetic evidence indicates that modern homo sapiens emerged out of Africa around 100,000 years ago into West Asia. One branch from West Asia went toward North, which again split – one branch going towards Europe and the other towards northern China. The other two branches coming from the West Asian area struck out through South China towards South East Asia, the other through India also to South East Asia. By this calculation, South Asia was peopled by Palaeolithic hunters and food gatherer around 65,000 years back.

Before we take up the case of the Indian subcontinent, there are certain broad issues that need to be examined. This pertains to the spread of agriculture and the second to the spread of Indo European languages. The Indo European group of languages cover a very large area indeed. If we leave out America and Australia where their dominance has been secured through a combination of the expansion of their numbers and genocide of the indigenous populations, they still cover entire Europe (barring a handful of languages) Northern India, and Central Asia. The question that has been raised is did the Indo European languages spread though conquest – use of horse, chariot and possibly iron – or did it take place through expanding agriculture due to the Neolithic revolution.

Cavelli-Sforza has been looking at genetic markers and their spread now for more than 40 years. Earlier, his work was based not directly on the genetic code but their expressions such as blood groups, Rh factors, etc. Since the 80’s, his group has catalogued actual genetic markers through DNA studies. In such DNA studies, it is important to separate the DNA and the expressions that are independent of those that are modified due to natural selection such as response to environmental changes. Fortunately, in the DNA code, 96% does not seem to be active: its change or mutation produces no discernible effect. This is known as junk DNA and changes in the junk DNA code provides an appropriate tool to analyse changes in genetic frequencies in different populations. The most important question that Cavelli-Sforza asked is that did farming spread throughout Asia, Africa and Europe or did farmers spread? Using his genetic markers and gene frequencies, Cavelli-Sforza’s answer is that it is the Neolithic farmers that slowly spread amongst the Palaeolithic hunters, food gatherers, a process he calls “demic” expansion. It is this model that today is increasingly validated as against the earlier diffusion models that proposed the spread by contact and cultural diffusion.

However, the case for “demic” expansion does not mean that the Neolithic farmers completely displaced the earlier Palaeolithic populations much in the way that modern homo sapiens replaced Neanderthals. Some have argued that the genetic composition of European changed but not significantly due to the Neolithic influx. Thus whichever studies are accepted, it is clear that amongst the current European population, Neolithic farmers radiating out of West Asia account for something between 10-27% of the total genetic contribution.