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Vol. XXV
No. 02
January 14,2001 |
People’s Democracy
Prabir Purkayastha
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 Renfres 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 zeros 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 80s, 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-Sforzas 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 Wilsons
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 80s, 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-Sforzas 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.
