KOLKATA: Crossing many borders, the Negrito tribes of Andaman islands share common ancestors with an indigenous tribe from Odisha and two others from Malaysia and Philippines, researchers say.
Genetic studies done by the Anthropological Survey of India (AnSI) has shown that the Jarawas and Onges of India's Andaman, Pauri Bhuiya of Odisha's Keonjhar, Semang tribe of Malaysia and Aeta of Philippines have a common parental stock.
"The presence of M31, the unique genetic markers found on their mitochondrial DNA, proves that all of them are offshoots of a single group of population which dispersed in different parts of the world over a period of few thousand years," AnSI anthropologist Dr Biswanath Sarkar told PTI.
Studies done after collecting blood samples of all the tribes and then matching their DNA profile show that the population had started splitting up in different waves around 35,000 years ago.In his recent book "Andaman Islands", researcher Dr Tilak Ranjan Bera writes that there are several hypotheses regarding the arrival of the aboriginal Negrito tribes in the Andaman islands.
"It is now postulated that the earliest modern human beings originated in Africa. The Negrito population from there migrated through the 'Horn of Africa', modern day Ethiopia in East Africa, to Arabia and along the coasts of South Asia (the 'Great Coastal Migration') and populated the rest of the world," he says.
During their passage to the Myanmar coast, they reached Andaman islands. "Hydrographic studies confirm the existence of an underwater mountain range from Myanmar to the Andaman islands. Cape Negrais of Myanmar is only 120 miles from the northernmost Andaman island....Lower water level, which occurs during the glacial period of the Ice Age, may also have played a role in the formation of a land bridge for a period," says Bera.
Anthropologists consider that the Great Andamanese were distinct, while the Jarawas, the Onges and the Sentinelese have similarities and originated from another faction of the Negrito population.
Among them, the Jarawas and Sentinelese are the only ones who are still living the life of hunter gatherers like the men of Stone Age. Unlike the Jarawas, the Sentinelese remain completely uncontacted and so no genetic studies can be done on them.
"The Sentinelese of the Andamans is possibly the only tribe in the world that does not maintain any contact with the modern world. They live isolated in the small 47 sq km North Sentinel island, situated on the west of Port Blair.
"They neither come to any other Andaman island nor do they allow anybody to live on their territory. They are still very hostile and attack with their bows and arrows when anyone tries to land on their island," says Bera.