A new study published in Science says the closest genetic ties for Native Hawaiians are with Rapa Nui, and points to Mangareva Island as the likely ancestral launching point for both populations. Alexander Ioannidis said the work uncovers where the native people of Hawaii had come from.
The finding lands with unusual force because Hawaii sits in a place that makes deep ancestry hard to trace: Ioannidis said it is the only Polynesian island in the Northern Hemisphere, and that it is a long way from everything. Hawaii and Rapa Nui are each more than 3,000 kilometers from the nearest inhabited island, yet the study says the two are the closest genetic match in the data.
To build that picture, the researchers analyzed previously published whole-genome sequencing data from 1,050 individuals across French Polynesia, added 12 unpublished genomes from Rapa Nui, and drew on genomic data from Native Hawaiians, Samoans and Tongans in the NIH's All of Us Biobank. They isolated Polynesian ancestry with the machine learning Gnomix analyzer and then used an identity by descent method to look for common ancestors. The result suggests that the history of Native Hawaiians may include a series of genetic bottlenecks, the kind that can sharply narrow variation in small founding populations.
That is where the story gets less tidy. The closest genetic ties point to Hawaii and Rapa Nui, but the study places Mangareva Island as the ancestral launching point for the modern populations of both places. In other words, the genetic signal appears strongest between the far-flung endpoints, even as the paper argues for a common source in between. The researchers had previously traced Polynesian migrations from Samoa to Fiji and Tonga, then toward the Cook Islands and the Society Islands including Tahiti, and this new work extends that reconstruction farther across Polynesia.
Polynesia spans more than 1,000 islands across a stretch of the Pacific Ocean the size of North and South America combined, and the study is another attempt to reconstruct that movement without written chronicles. For Native Hawaiians, the paper offers the clearest genetic answer yet to a question that has long been answered only in broad terms: the trail does not stop at Hawaii, and it does not run in a straight line. It runs through a chain of small populations, long crossings and a history that still leaves one open question hanging in the middle — how the movement from Mangareva carried ancestry to both Hawaii and Rapa Nui.
