Traditional knowledge handed down from generation to generation helped to save ancient tribes on India's Andaman and Nicobar Islands from the worst of the tsunami, anthropologists say.
Officials hope all evacuated tribespeople can soon return home
But other isolated communities who moved to the islands from South East Asia centuries ago fared far worse than the indigenous peoples, evidence suggests.
The aboriginal tribes - some of the oldest and most isolated in the world - have oral traditions apparently developed from previous earthquakes that may have allowed them to escape to higher ground before the massive tsunami struck the island chain off Indonesia.
The Onge tribe, for example, have lived on Little Andaman for between 30,000 and 50,000 years and, though they are on the verge of extinction, almost all of the 100 or so people left seem to have survived the 26 December quake and the devastating waves which followed.
Their folklore talks of "huge shaking of ground followed by high wall of water", according to Manish Chandi, an environmental protection worker who has studied the tribes and spoke to some Onges after the disaster.
"When the earthquakes struck, the Onges moved to higher ground deep inside their forest and escaped the fury of the waves that entered the settlements," he told the BBC News website after talking to some of the inhabitants who knew some Hindi as well as their own ancient languages.
He said another aboriginal people - the Jarawa on South and Middle Andaman - also fled to higher ground before the waves.
"There's clear evidence that the aboriginals know about tsunamis and they know how to deal with them," he said.
Samir Acharya, convenor of the Society for Andaman and Nicobar Ecology (Sane), said the aboriginals have a collective memory of earthquakes and tsunamis so they knew to move to higher ground.
Some say the Great Andaman tribe came originally from Africa
Madhusree Mukherjee, author of The Land of the Naked People, supported the theory, saying: "The aboriginals have an island survival strategy that they have developed through the knowledge of the generations."
Anthropologists and government officials compared notes on the tribes' behaviour after the huge undersea earthquake that triggered the Indian Ocean tsunami that is now known to have killed more than 200,000 people in the region.
KC Ghoshal, executive secretary of the Andaman-Nicobar tribal welfare department, spoke to some of the Great Andamanese people taken to a rest house near the islands' capital, Port Blair.
He said the survivors spoke of feeling the earth shake and bringing their thatched huts crashing down, prompting an exodus to higher ground.
"We can now say we have contacted or carefully assessed the plight of the aboriginals and we can say almost of them are safe," he said, adding that officials hoped to return those taken to temporary shelters in the immediate aftermath.
"They have been much harassed by the media and we plan to send them back to their areas without much delay," Mr Ghoshal said.
Mr Chandi, who travelled to the affected areas as part of a team assessing the tsunami's environmental impact, said his research showed the Onges living at Dugong Creek and South Bay on Little Andaman Island were also almost wholly safe.
He added that the Jarawa tribe along the west coast of South and Middle Andaman Islands was also largely safe.
Great Andamanese - 40-45 people on Strait Island
Jarawa - about 40 people on South and Middle Andaman
Onge - 105 people on Little Andaman
Shompen - 200-250 people on Great Nicobar
Sentinelese - about 250 people on Sentinel Islands
Most of the Jarawas appeared to be deep in the jungles, hunting wild boar, and staying away from the beaches where they would usually catch turtles - another favoured food.
Further afield, the Sentinelese people appear not to have been affected, Mr Ghoshal said.
"They continued to remain isolated and even shot arrows at a naval helicopter on patrol which had descended on the North Sentinel island to check," he said.
There are some concerns for the Shompens, the last of the islands' five groups that are considered native, though some say they may have originated in Africa.
The Shompens live inland and deep in the forest, and the government's tribal welfare department is not sure how many, if any, casualties they suffered.
"A helicopter that hovered over their habitat seems to have scared them and they have fled into very dense jungles. So it will be a while before a clear assessment will emerge," Mr Ghoshal said.
But research on the more southern Nicobar part of the archipelago suggests that tribes who were not indigenous to the islands fared far less well.
Threats still remain for survivors - mostly from the outsiders' diseases
Thousands of Nicobarese, who some say migrated from South East Asia 500 or 600 years ago, are dead or missing. Many of their islands suffered more in the huge waves - in some cases being washed off the horizon entirely.
And even those who survived face more dangers along with their aboriginal fellow island dwellers - partly because of the renewed interest in them from outside.
Andaman health expert Tilak Bera, an Indian navy doctor with close knowledge of the aboriginals, said: "They can cope with tsunamis but they will find it difficult to cope with disease that the settlers have brought to the islands.
"I am sure they have tided themselves over the tsunami with their collective knowledge but I am apprehensive about diseases that may afflict them because of the exposure to outsider society and unfamiliar food they had to eat after displacement."
It may yet be a sad repetition of history for the tribespeople.
In the 19th Century - when the last massive earthquake struck the Indian Ocean - many thousands died in measles, pneumonia and cholera epidemics when they came into contact with outsiders.