Genetics of South Asia
Genetically speaking, South Asia extends beyond the borders of India and Pakistan
B R SINGH
Worldwide, much research is being done on the genetics of various people inhabiting the planet. Unlike the animal kingdom where different species of the same genus differ genetically to the extent that they can no longer interbreed all humans are the same species, Homo sapiens sapiens, the only extant species of the genus Homo. Current theory has it that anatomically modern humans (AMH) originated about 200,000 years ago in the region of the Omo river in South West Ethiopia from where they spread out in all directions to populate the globe. In the course of their wanderings over tens of thousands of years different sets of genes mutated in different migrating populations in a process called single nucleotide polymorphism (SNP or Snip). Some snips were beneficial and were passed on to offspring, others were harmful and their carriers died out. Particular groups of humans thus began to carry particular sets of mutations. These snips are the markers scientists use to identify different races.
National Geographic magazine was the first to popularize genetic testing. In a famous project it undertook to study the genetic diversity of people inhabiting the Astoria section of Queens in New York. 193 volunteers from different parts of the world now living in Astoria took part in the study. The study discovered that between them they carried markers for virtually all the population groups on earth. Other more academic projects have been undertaken abroad to study gene variations in human populations. For some reason the Government of India has declined to join them or permit their testing DNA of Indians. It is conducting its own study but is coy about revealing the findings. There are other projects such as 'Hapmap' and the Human Genome Diversity Project run by Stanford University engaged in the business of charting gene variations. Ajmal Zachariah, a Pakistani at Georgia Tech University runs a project called the Harappa Ancestry Project. It can be accessed at
Harappa Ancestry Project | Genetics and South Asia. The latest study to hit the headlines is the one conducted by Harvard Medical School and the Centre for Cellular and Molecular Biology in Hyderabad.
It seems that modern Indians and Pakistani including remote tribals have two major components to their DNA, Ancestral South Indian (ASI) and Ancestral North Indian (ANI). ANI seems to be associated with West Asia, Europe and the Caucasus region, and ASI with people on the Andaman Islands. The Harvard study analyzed DNA from 371 people belonging to 73 groups from all over the subcontinent and found that mixing of ANI and ASI started about 4000 to 5000 years ago and stopped 2000 years ago. Coincidentally it was about 2000 years ago that the strict caste codes of the Manusmriti prohibiting marriage outside caste took hold.
The Harappa project collects DNA data from South Asians in the US but also from other communities. It is then run through a software programme called Admixture. Admixture shows up the different component of an individual's DNA in designated clusters. The Harappa project while retaining ASI as it is broke ANI further into three groups, Baluch, Caucasian and North East European. The Admixture software displays the ASI, Baloch, Caucasian and NE European components of the individual's genetic code. One of the surprising outcomes of the project is the wide dispersal of ASI. It is found as far West as Iran and in Tajikistan to the North. In Afghanistan, Pakistan and North India it forms a substantial portion of inheritance. Pathans have about 22% ASI on average, Punjabis between 25% and 35% depending upon community; Kashmiri DNA also comprises over 30% ASI. All South Asians including the Pathans have a substantial component of Baloch DNA. It varies between 35% and 45% for North Indians including Kashmiris and Punjabis. The Caucasian and North Eastern European strands vary between 20% and 28% for Punjabis, and is highest among Haryana Jats, higher even than Brahmins of Punjab and Kashmir. Overall, North Indians have about 70% ANI. The figures vary slightly between communities.
It would seem then that genetically speaking, South Asia extends beyond the borders of India and Pakistan. The Pakhtun region of Afghanistan is certainly South Asian because the Pakhtun communities share 85% of their DNA with Punjabis and nearly 90% with Jats. Even Tajiks have a hefty amount of ANI-Just below 10% of ASI, but 32% of Baloch. Iranians surprisingly also show 4% ASI and 25% Baloch; they carry around 40% Caucasian genes but a lower North East European percentage than Pathans and Punjabis.
A gene cluster named Baloch or ASI does not mean that it originated in Balochistan or South India, only that it is the most frequently occurring group in the population of that area; it does not say anything about the geographical origin of the mutation. We all carry the same set of genes that make us human; it is the tiny proportion of mutated genes that tells us about the wanderings and interbreeding of our ancestors that created communities with their particular admixtures. Who is to say why ASI is found as far north as Byelorussia and Azerbaijan?
India is a strange land where strange things happen. It is a pity that the Central Government has not been responsive to international gene typing projects. Genome projects at foreign research centres have had great difficulty collecting samples from India. What could be the reason for this reluctance considering that India is ever willing to jump aboard international scientific cooperation experiments? Could there be a political motive?
Indian diversity, which all Indians know about and happily live with, rubs uncomfortable shoulders with the official narrative of India. This originated in the imagination of Jawaharlal Nehru when he "discovered" a mystical unity about India stretching back into remote time. After independence the narrative became official. It may be seen in those nice ads on TV that have famous artists singing 'mile sur mera tumhara' in various styles and languages conveying a unity in India's diversity. It is a very nice video, sensitively done, but somewhat forced. Sometimes this force manifests in pseudo science such as the 'Out of India' theory (OIT) posited by Hindutva nationalism to counter the Aryan Invasion Theory (AIT). OIT says that India is the original homeland of the Aryan race from which it migrated to populate central Asia and Europe. Historians now accept that there was no Aryan invasion, and anthropologists are agreed that there never was an Aryan race, so the whole controversy is moot. It is agreed generally that there were migrations of populations from Central and West Asia into India starting in the mists of prehistory and continuing well into the era of recorded history. Arya only meant noble or high born.
Is it likely that the objection to joining foreign based genome projects is based on the fear that evidence of the genetic diversity of India will undermine the political narrative, particularly that of the BJP, that Indians far from being of 'Indian' stock are actually a genetically diverse bunch united more by culture and civilization than by genes.
These genetic studies also affect the unofficial narrative of Pakistan. If Pakistanis have the same bloodlines as those found in North India then all that talk of being descended from Arabs and Iranians or central Asian conquerors goes out of the window. The Pathan claim of being the offspring of a lost tribe of Israel, or of being descended from some mythological Arab ancestor must also be discarded because their DNA shows no Bedouin lines, or anything in common with Ashkenazi Jews. The Pakistani lawyer and politician Aitzaz Ahsan, following upon Nehru, wrote about his own discovery of Pakistan in a book called The Indus Saga, a rather contrived post colonial narrative much inferior to the original product.
It is often asked how genes can be similar if appearances differ so markedly. Biologists distinguish between genotype, an organism's full genetic inheritance, and the phenotype, the physical appearance which is a result of how genes express themselves. Even an identical genetic inheritance can produce slight differences in phenotype. An individual's genotype is the genetic code they carry in their cells. Their phenotype is the visible, expressed trait, such as hair or skin colour. The phenotype depends upon the genotype but can also be influenced by environmental factors.
Migrations continue everywhere, especially in the new world and Australia. Slowly but surely the profile of populations is changing except perhaps in countries such as Japan and Saudi Arabia. The US must be world's largest laboratory of human genetics at this time considering its massive intake of migrants from all over the world. Endogamous caste marriages prevented a homogenization of Indian populations, but that is not likely in the US. Already as the National Geographic experiment shows, all human gene mutations can be found in one small borough of New York. It is only a matter of time before a new admixture comes to dominate the United States. In a couple of thousand years Americans will be a different lot from what they are now.
Genetics of South Asia Lastupdate:- Sun, 1 Sep 2013 18:30:00 GMT GreaterKashmir.com
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