MIGRATION PUZZLE - Who went where, when?



The Brokpa villagers who ive near Batalik in Ladakh are a colourful but confused lot. Their oral history and songs suggest that they migrated from Gilgit, now in Pakistan-occupied Kashmir (PoK), a few hundred years ago. But over the last 50 years they've come to believe that they're remnants of an ancient Aryan population that came to India with Alexander's army.

The "Aryan" theory was floated by a few German Indologists in the 1960s; it caught everyone's fancy, and the Brokpas turned it into a marketing tool. The problem, however, is that nobody takes it seriously any more and the small, isolated community which had almost convinced itself about the supposition, is now unsure of its roots.

So recently when a group of researchers landed up at their villages, promising to tell them about their genetic history, the Brokpas were excited. The Aryan Welfare Association in Dha village swung into action, organizing a camp at which men from different villages came together to take swills of distilled water and spit into vials.

For the Brokpas, it was a solemn occasion. This, they were told, would hold the clue to their origin.

In distant Madurai, Ramasamy Pitchappan is now busy analysing the spittle. As principal investigator in India for the Genographic Project, he has spent the better part of the last few years collecting samples from different tribes, castes and linguistic groups across the country.

The goal of the project, a collaborative venture between the National Geographic Society, IBM and the Waitt Family Foundation, was to study the patterns of human migration, from the first exodus out of Africa to more recent ones.

They hoped to do this by looking at the patterns of DNA mutations across the world.
The spread of these mutations or markers , would be indicative of human movements.
The search was further narrowed to mutations in mitochondrial DNA and the Ychromosome, both of which, unlike other genetic material, are passed intact down the generations. A chance mutation in either of these would, therefore, also be inherited intact.

One such mutation, known as the M130 marker, had provided evidence of the first migration of man from Africa to Australia, through south India.
It was discovered in 2001 by Pitchappan, working in collaboration with noted geneticist Spencer Wells, in a small group of people in Jyothimanickam village near Madurai.

The carrier, Virumandi Andithevar, an unsuspecting 30-year-old systems administrator, had been declared the first Indian.

The Genographic Project was started in 2005 to assess the distribution of such markers, and discover new ones.

Similar studies had been done in India, but they d been much more localized and the sample sizes were smaller.

The India operations started a year late but has already collected the 10,000 samples they d aimed to gather, Pitchappan says proudly.

Over the last four years, his small band of researchers has fanned out across the country, visiting communities that have been selected for their uniqueness, size and recorded histories. We ve tried to select groups that are likely to have divergent migratory histories, explains Pitchappan.

The Meitei of Manipur were selected for being the only Vaishnavites in the region; the Garo of Meghalaya by virtue of being the only tribal community that allows marriage between first cousins; the Jenu Kuruba, honey gatherers from the forests of Nagarhole, for their unique profession; and the residents of Malana in Himachal Pradesh for their self-imposed isolation.

Convincing these communities to take part in the study was not always easy. It took researcher V.S. Arun a few days to persuade the residents of Malana to part with their samples. The problem, he says, was that we needed to give them distilled water for the samples, but their laws forbade them from accepting food or water from outsiders.

In the end it took the intervention of the village council to sort out the impasse.

The tiny Sunni community in Nyoma, on the India-China border in Ladakh, initially accused the researchers of practising black magic. Their origins, they told the researchers, were determined by God, not by spit. Later, it emerged that the problem was neither God nor spit, but a Shia who was acting as the team s interpreter.

The coaxing and the cajoling has, however, paid off. Some of the preliminary results of the project are emerging, and the complicated knot of migration routes into, out of and within India is unravelling.

The findings indicate that there have been two major migration routes into India, one along the coastal route from Africa to India and the other through the Khyber pass.

Looking at India as a whole, says Pitchappan, the most common marker is the H group, but we ve found its frequency to be the highest in a few hill tribes of south India.
The implication? The first populations in India probably settled in those parts.

As they migrated to other parts of the country, new markers emerged. The O group emerged in north-east India and spread in Tibet, Myanmar and parts of South-East Asia.

The L group remained confined to Tamil Nadu and parts of south India, limited by small-scale local migrations.
The M45 marker, on the other hand, spread to Central Asia and onwards to Europe. It also came back to India through later migrations in the opposite direction.

The R1A1 marker emerged in north India, and is also surprisingly found in lower frequencies among the Brahmins of Tamil Nadu. Pitchappan believes that its distribution in the south correlates with the movement of Brahmins from north to south during the Cho a period. Much more remains to be discovered. Detailed migration patterns will emerge, says Pitchappan, as more of the 10,000 samples collected so far are processed. Field trips to large parts of the country such as Maharashtra, Gujarat, Madhya Pradesh and Uttar Pradesh will also take place in the first half of 2010. By the end of the year his team is hoping to publish studies correlating migration with language and caste formation in small groups in India.

It s an exhilarating and challenging project, says Subhadeepta Ray, a researcher at the Delhi School of Economics who has been studying the interaction of sociology and genetics that such projects entail.

The work so far has been very thorough and detailed.

Pitchappan has yet another agenda for the project. I hope, he says, that once people understand the biological basis of their differences they will become a little more sensible about issues like caste and religion.

Meanwhile, the Brokpas wait anxiously for their results.

Source:LIve mint