Scientists Decipher History of Polynesian Colonization Engraved in DNA of Today’s Pacific Islanders | The Weather Channel – Articles de The Weather Channel


A seemingly curious moai nods while pondering an observation.

(Lieutenant Elizabeth Crapo / NOAA Corps)

Tucked away in a corner of the vast Pacific Ocean lies the legendary Polynesian Triangle: with the American Hawaiian Islands to the north, New Zealand to the southwest, and Easter Island to the southeast. These islands are spread over a large area of ​​the Pacific, covering an area of ​​40 million square kilometers.

Evidence suggests that people from Southeast Asia first sailed to the Polynesian islands around 1,500 years ago. These people settled on various beautiful islands that the Polynesian Triangle is home to over the following years.

But how did they get from island to island thousands of miles apart? Without modern navigation systems, how dare they dare the rough seas? Although this is one of mankind’s most adventurous journeys, we know very little about the origin and migration of the Polynesians, leaving anthropologists perplexed as to the reasons for their dispersal and the place where it all began.

Origin history of the Polynesians

The first Polynesians are not known as the greatest navigators in history for nothing! By jumping aboard their double-hulled canoes, these sailors succeeded in colonizing distant islands with only the sun, moon, stars, planets and clouds as guides, thus their relationship with mother. nature was deeply rooted. As romantic as it sounds, there was a lot of science involved in the success of their travels!

In a new study, an interdisciplinary team of researchers sketched out a scenario about the when and how of the mysterious Polynesian migrations using genetic tools. Stanford University computational biologist Alexander Ioannidis, population geneticist Andrés Moreno-Estrada of the National Genomics Laboratory for Biodiversity in Irapuato, Mexico, and their colleagues attempted to answer the long-standing question: All Are Polynesians from the same stock?

Two major clues suggest that all Polynesians came from the same population. The famous British explorer, Captain Cook, revealed the first evidence when he set foot in Tahiti in 1769. On his way to the neighboring islands of Polynesia, he realized that groups of all these land masses different and distant spoke similar dialects!

The giant monoliths or Moai – resembling a human face – probably carved to commemorate and possibly revere ancestors served as second evidence. While the Easter Island monoliths are quite famous, other islands also have similar monoliths depicting human faces. This discovery further reinforces the idea that all Polynesians have a common origin. But the question that remained to be resolved was where the sailors migrated and can we prove their origin empirically.

It’s all in the genes!

Dr Ioannidis and his colleagues wanted to see if they could use today’s genomes to determine when and where the first Polynesian settlers landed on each island. They uncovered the genetic history of Polynesia using genomic data from 430 modern people from 21 Pacific island populations.

The plan was to use ancestry algorithms to look for unusual features in the genomes of today’s Polynesians. It is a calculation method based on the concept of “genetic bottleneck”.

Any rare genetic mutations they possessed were passed on to the next generation if a small group of individuals embarked and settled on a new island. Then, if a second group broke up from the first to inhabit another island, they would take the rare genetic trait with them.

Scientists intended to reconstruct the first migration routes by analyzing the unusual characteristics of modern Polynesians, such as those that increase the chances of contracting certain diseases and ailments. Genetic history has helped researchers resuscitate Polynesian ancestry and trace their eastward migrations.

Navigate to conclusions

Shown above are distinctive monolithic sculptures designed by the inhabitants of the Marquesas Islands (top), Mangareva (center), Raivavae (bottom left) and Rapa Nui (bottom right).  (Zaira Zamudio Lopez)

Shown above are distinctive monolithic sculptures designed by the inhabitants of the Marquesas Islands (top), Mangareva (center), Raivavae (bottom left) and Rapa Nui (bottom right).

(Zaira Zamudio Lopez)

DNA analysis revealed the chronology and population sequence of an area covering about a third of the Earth’s surface, with Samoa as a starting point. They then reached the Cook Islands (Rarotonga) in the 9th century, the Society Islands (Tōtaiete mā) in the 11th century, and the Western Austral Islands (Tuha’a Pae) and the Tuāmotu Archipelago in the 12th century. Rapa Nui, better known as Easter Island, and other megalithic sites rich in statues were the last to be inhabited.

Towards the end of these first migrations, islands known for their stone statues settled: Nuku Hiva and Fatu Hiva in the North and South of the Marquesas, Rapa Nui and Raivavae, which is part of the Tuha’a Pae. Dr Ioannidis said the four island groups with the monolithic statues are also the most closely related genetically, even though they are actually in different geographic locations.

Researchers found that settlers found Rapa Nui around AD 1210 after a 1,600 mile (2,575 km) deep sea expedition. However, this chronology is somewhat later than suggested by archaeological and geological evidence, between the late 1000s and the early 1100s. Historians believe that family groups of 30 to 200 people were sailing in both the late 1000s and early 1100s. Double-hulled canoes with a Latin or triangular sail which behaved like the current catamarans.

However, despite extensive genetic analysis, some discrepancies remain between the new study and the previous ones. Tracing the evolution of languages ​​and the emergence of distinct dialects as populations migrated to different islands is one of them. These studies show a lot of inter-island contact during these eastward migrations, while the hypothetical migratory sequence of the new study suggests relatively little inter-island contact.

Yet it seems that independent lines of genetic, linguistic and archaeological data converge to convey a similar account of what is called the “short chronology” of eastern Polynesia.

The landmark study was published last week in Nature and can be viewed here.

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