Scientists have discovered how the first seafarers settled the islands of the Pacific Ocean

The settlement of the Far Pacific was one of the most remarkable episodes in human expansion.

Around 5,000 years ago, groups of people of East and South-East Asian descent began to spread across the islands. Around 3,000 years ago, seafarers had already reached the previously uninhabited archipelagos of Vanuatu, Fiji and Tonga.

To do so, they had to cross significant stretches of open ocean — a feat that required advanced maritime technology and navigational skills. Previous genetic and archaeological studies had also shown that the initial expansion into the Pacific took place very rapidly and that the early inhabitants of Vanuatu and Tonga had virtually no Papuan genetic component.

But the new study shows that this initial migration was only the beginning.

Details

An international team of scientists has obtained new genomic data from the skeletal remains of 72 ancient individuals, spanning approximately three millennia of history in the western part of the Pacific.

The samples from Fiji proved particularly significant — previously, there were virtually no ancient human genomes from this region.

The genetic picture revealed two major waves of settlement.

The first was predominantly associated with a population whose origins were related to groups from East and South-East Asia. It was this expansion that rapidly reached Vanuatu, Fiji and Tonga.

Later, another genetic component appeared on the islands — one linked to the populations of New Guinea and Near Oceania.

And it spread in a completely different way.

According to genetic data, an ancestry linked to Papuan populations was already present in Vanuatu around 2,700 years ago.

However, it did not appear in Fiji, situated further east, until some 500 years later.

In other words, the first major expansion traversed this part of the Pacific relatively quickly, whilst the subsequent wave spread much more slowly.

Previous studies of ancient DNA had already shown that the Papuan component reached the Pacific after the initial settlement and spread through subsequent migrations and population mixing. The new data allow us to reconstruct the chronology of this process much more accurately.

The researchers also found evidence of yet another wave that reached Fiji later. It may have come from neighbouring archipelagos, including Vanuatu.

Thus, the history of the region’s population appears not as a single journey from point A to point B, but as a millennia-long network of migrations between the islands.

Another finding relates to the enigmatic ‘Polynesian outliers’.

This is the term used to describe communities located outside the traditional Polynesian Triangle but which retain Polynesian languages and cultural characteristics.

Such groups exist, for example, in Vanuatu.

Genetic data has revealed direct evidence of Polynesian migration to the southern part of Vanuatu around 1,000 years ago.

This means that human movement across the Pacific was not one-way. After settling the islands far to the east, individual groups set off westwards again and established new communities.

Such reverse migrations had previously been hypothesised on the basis of modern genomes, but new ancient DNA allows us to observe them directly in the past.

But the study went beyond examining the migrations of entire populations.

Scientists studied in detail a community that lived in Fiji around 1,500 years ago. Using ancient DNA, the researchers were able to establish kinship links between the buried individuals and reconstruct a family line spanning five generations.

And here, another unusual detail came to light.

The genetic component associated with the later Papuan migration was distributed unevenly amongst the community’s inhabitants. One group of biological relatives differed markedly in origin from the others.

The authors suggest that this may have been linked to social norms that allowed a particular family to retain wealth or high status across several generations.

However, DNA alone does not allow us to determine how wealthy or influential these people were. This involves reconstructing the social structure based on a combination of genetic kinship and archaeological context.

There is an important limitation when interpreting the results.

The terms ‘Southeast Asian ancestry’ and ‘Papuan ancestry’ describe the genetic similarities of ancient populations, rather than modern peoples or the ethnic identity of specific individuals.

The results therefore cannot be reduced to a scenario in which one modern ‘people’ arrived on the islands and was replaced by another.

On the contrary, ancient DNA reveals a long history of movement, contact and intermingling among various population groups.

Modern genomics has already shown that the settlement of the Pacific was characterised by multiple migrations and repeated contacts between the islands, rather than a single wave.

Why this is important

The study challenges our understanding of how people settled the vast expanses of the Pacific Ocean.

The first seafarers were able to cover thousands of kilometres in a relatively short time and reach remote islands. But the region did not remain isolated after that.

Over the following millennia, people continued to move between archipelagos, intermingle with other groups and sometimes even return westwards.

And ancient DNA now allows us to see this history not only on the scale of entire waves of migration, but also at the level of specific families who lived on the islands one and a half thousand years ago.

That said, the study focuses primarily on the western part of the Pacific – Vanuatu, Fiji and neighbouring regions – so its findings cannot automatically be extrapolated to the entire history of settlement in the Pacific.

Source

Study: Michal Feldman et al. Ancient genomes reveal distinct human dispersals and social stratification in the settlement history of western Remote Oceania.

Journal: Cell, 2026.