Over a millennium ago, seafarers reached the islands of Polynesia in sailing canoes. This is how the planet's last habitable region to be settled by people became populated.

The timing and sequence of the settlement of this corner of the Earth were deciphered by a genetic study, which found that the settlement began with Samoa Island and ended with Easter Island (known for its huge statues) and other locales. 

The study found that Rapa Nui (Easter Island) was settled in around 1210 AD after a sea voyage that covered an enormous distance of 2,575 km. Historians believe that groups of 30-200 people sailed in double-hulled canoes to reach the island.

"Each living individual retains a genetic record of all the ancestors from whom they inherited their DNA, so by analyzing together hundreds of individuals, we can create a genomic network where connections, splitting patterns and dates can be inferred," said geneticist and study co-author Andres Moreno-Estrada of Mexico's CINVESTAV network of research centers.

The first voyages began with Samoa, moving on to Fiji and Tonga, and then Rarotonga in the Cook Islands in the 9th century. The second wave of voyages began in the 11th century, settling Society Islands, followed in the 12th century by the Austral Islands, ending with the last islands that include Easter Island, the Marquesas Islands, and other locales, which were settled in the 12th and 13th centuries.

“Many of the distances were immense,” said Stanford University computational geneticist Alexander Ioannidis, lead author of the research appearing in the journal Nature.

Chap 2 is out! (Chap 1 was Ioannidis et al. “Nat. Am. gene flow into Polynesia,” Nature 2020.) We answer centuries-old questions🗿 using mostly published modern-day SNP data, highlighting many ancestry specific methods: it’s how you analyze📐it!https://t.co/Np0aYsKvT5

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— Alexander G. Ioannidis (@alexGioannidis) September 22, 2021

Navigation might have happened thanks to ships following the paths of long-distance seabirds and the use of astronomy. 

The study found that the people inhabiting these island chains were genetically connected and had a common genetic source.

Even though the voyages began with Samoa, it is believed that it was an intermediate stop in the chapter of human expansion that began in Taiwan around 4000 to 5000 years ago. Samoa, scientists believed, was settled by around 800 BC.