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Easter Island’s famous megaliths have relatives on islands thousands of miles to the north and west, as do the people who created them, according to a study released Wednesday.
Research has shown that over a period of 250 years, distinct groups of people moved from tiny islands east of Tahiti to Easter Island, the Marquesas and Raivavae – archipelagos thousands of miles apart. kilometers but all housing similar ancient statues.
“These statues are only found on islands that are genetically closely related,” lead study author Alexander Ioannidis of Stanford University told AFP.
Using cutting-edge modern DNA analysis, Ioannidis and his team were able to map and date the colonization path of early Polynesians, which began in Samoa and stretched across the Pacific between the 830s and 1360s.
“It was an open issue ever since Captain Cook first noticed that the people of the Polynesian islands all spoke the same language,” Ioannidis said.
The expansion happened quickly — over about 17 generations — outpacing any major changes in language or culture that might have served as markers, the results show.
The researchers were able to piece together the trans-Pacific migration puzzle by comparing the genetic material of 430 current inhabitants of 21 islands.
The outward expansion of Samoa proceeded west to Fiji, Tonga in the south, and then Raratonga in the east around the year 830.
– “Small islands in the shape of rings” –
A few hundred years later, descendants of Raratonga traveled to settle in present-day Tahiti and the Tuamotu Archipelago just beyond.
It is from the small, long-neglected sandbar islands of the Tuamotu that the most ambitious forays are starting, Ioannidis said.
Today sparsely populated thanks in part to their role as nuclear testing grounds, the Tuamotus extend over an area equal to the distance between England and Greece.
The study notes that the low islands likely emerged below sea level just a few hundred years before Polynesians settled there.
“They needed a maritime culture to move between these little ring-shaped islands,” Ioannidis said.
“I think that partly explains why that’s where the longest trips start from.”
This became ground zero for the megalith-building peoples who came to inhabit the Marquesas, Rapa Nui (Easter Island) and Raivavae.
The timing of these expansions matches earlier DNA-based findings by Ioannidis and his team showing that Native Americans—likely from the northwest coast of South America—and Polynesians mixed around AD 1200.
– Ancient clues in modern DNA –
“The date we found for this contact is very close to the dates we find for these voyages from the Tuamotu to colonize these remote islands,” Ioannidis said.
Today’s Polynesian populations have a mixed heritage, with traces of Europe, Africa, and other places in their ancestry.
While genetic studies of ancient peoples have tended to focus on ancient DNA samples discovered at archaeological sites, Ioannidis said his team has been able to zero in on telltale sequences buried in modern DNA.
They used software to analyze samples from 430 inhabitants of 21 different islands to identify recurring genetic patterns specific to Polynesians, blocking out DNA sequences associated with European or other ancestry.
Otherwise, “you would just find that the islands with the ‘more Polynesian’ DNA were more related,” Ioannidis explained.
“It’s not historically interesting.”
His team used the genetic clues to draw a kind of family tree across the Pacific, from east to west.
Since DNA strands get shorter as they are recombined over generations, the length of the shared segments revealed the number of generations passed between each colony.
© 2021 AFP