DNA Study Links Native Hawaiians and Easter Islanders to a Shared Polynesian Voyaging Group

The genetic connection between Native Hawaiians and Easter Islanders points to a shared chapter in Polynesian settlement: both populations descend in part from a group of long-distance voyagers rooted near Mangareva. The finding also highlights how repeated settlement by small groups shaped Polynesian genetic diversity, with potential relevance to health research.

A shared ancestry across the Pacific

Hawaii and Rapa Nui, also known as Easter Island, sit about 4,500 miles (7,200 kilometers) apart. They are the most distant Polynesian islands from one another, within a region of more than 1,000 islands that covers an expanse of the Pacific roughly comparable to North and South America combined.

To trace connections across that distance, researchers analyzed genomes from 1,050 people living across Polynesia, including 317 Native Hawaiians and 12 people from Rapa Nui. They compared shared stretches of chromosomes: longer matching segments generally indicate that two people had a common ancestor more recently.

The results, published Oct. 8 in Science, showed that the Indigenous populations of Hawaii and Rapa Nui were the most genetically related to one another among the groups examined. “This was really shocking at first — these islands are so distant from one another,” said study co-author Alexander Ioannidis, a computational geneticist at Stanford University, in an interview with Live Science.

The researchers’ explanation centers on a shared “ultravoyager” population associated with the Mangareva islands. Mangareva lies about 3,440 miles (5,530 kilometers) southeast of Hawaii and 1,600 miles (2,600 kilometers) west of Rapa Nui. The study suggests that ancestors of both island populations spent time together as a common group after separating from an ancient Mangareva population. From there, some traveled to Hawaii, while others reached Rapa Nui.

Ioannidis said that evidence for a group capable of reaching one distant island makes a voyage to the other more plausible. The wider region around Mangareva includes the Austral, Society and Marquesas islands, as well as the Tuamotu Archipelago. “Sailing in-between these islands would have required skilled navigation,” he said. He argued that experience moving through this vast network could have supported later journeys to Hawaii and Rapa Nui.

The interpretation also fits earlier genetic evidence. In 2020, researchers reported that members of the ultravoyaging group had ancestry from Indigenous people in what is now Colombia. The location of that contact remains uncertain: it may have happened on an island or on the South American continent.

Archaeological evidence offers an independent check on the genetic account. Patrick Kirch, an archaeologist at the University of Hawai‘i at Mānoa who was not involved in the study, told Live Science that the findings “agree very well with what we see archaeologically.” When evidence from different disciplines converges, he said, it gives researchers greater confidence in the result.

Settlement patterns left a strong genetic imprint

The study also examined founder effects: changes in genetic variation that can occur when a new population begins with a small number of people. If a rare variant is present among the founders, it can become more common as their descendants multiply. Ioannidis described how a trait found in only a few initial settlers may later affect a larger share of the population.

Across the Polynesian populations studied, the researchers found repeated founder effects. A small group would settle an island, and descendants from that population could then form another small group that traveled onward. This pattern of settlement left successive genetic traces.

Research has documented founder effects among people of European descent, including the Amish, Finns and Ashkenazi Jews. The new analysis points to an even larger effect among Native Hawaiians: the founder effects measured were more than 10 times those seen in the European populations used for comparison.

Kirch said founder effects can shape more than genetic diversity. They may also help explain shared cultural and linguistic features across eastern Polynesia, whose populations trace back to a central group.

Potential relevance to health research

The researchers identified three genetic variants that are very rare globally but appeared in 2% to 3% of the eastern Polynesians they studied. The variants are associated with dislocated eye lenses, progressive vision loss and kidney failure.

Ioannidis said these findings point to a need for more research into variants with possible clinical significance among Native Hawaiians. He described opportunities for precision health research in a population he said is twice the size of the U.S. Amish population. The study’s genetic history offers a starting point; understanding how specific variants affect health will require further investigation.