Polynesians and South American people shared DNA 800 years ago
People from four island sites in French Polynesia - Mangareva and the Pallisers in the Tuamotu archipelago and Fatu Hiva and Nuku Hiva in the Marquesas Islands - bore DNA indicative of interbreeding with South Americans most closely related to present-day indigenous Colombians at around 1200 AD.Updated: Jul 09, 2020 15:15 IST
New genetic research shows that there was mingling between native people from Polynesia and South America, revealing a single episode of interbreeding roughly 800 years ago after an epic transoceanic journey.
The question of such contact - long hypothesised in part based on the enduring presence in Polynesia of a staple food in the form of the sweet potato that originated in South and Central America - had been keenly debated among scientists.
According to a paper titled Cumal to Kümara: The Voyage of the Sweet Potato Across the Pacific by the University of Hawaii, “The introduction of the sweet potato into the Pacific is the source of multiple theories, which cite both human and natural agents. The sweet potato is native to South America, where it has been cultivated for approximately 4,000–5,000 years by indigenous communities. Evidence of the sweet potato has also been found in sites on Aotearoa (New Zealand), which predate western contact by centuries.”
Scientists said on Wednesday an examination of DNA from 807 people - from 14 Polynesian islands and Pacific coastal Native American populations from Mexico to Chile - definitively resolved the matter.
People from four island sites in French Polynesia - Mangareva and the Pallisers in the Tuamotu archipelago and Fatu Hiva and Nuku Hiva in the Marquesas Islands - bore DNA indicative of interbreeding with South Americans most closely related to present-day indigenous Colombians at around 1200 AD.
These islands are roughly 4,200 miles (6,800 km) from South America.
People from Chile’s Rapa Nui, or Easter Island, also had South American ancestry, some from modern Chilean immigrants and some from the same ancient intermingling as the other islands. Rapa Nui, located 2,300 miles (3,700 km) west of South America and known for its massive stone figures called moai, was settled some time after the interbreeding 800 years ago.
According to sciencenews.org, “Ideas about how remote Polynesia came to be populated have long inspired scientific debate. Norwegian explorer Thor Heyerdahl’s 1947 Kon-Tiki expedition tested his idea that South American seafarers settled the Pacific islands, including Rapa Nui, showing that it was possible to drift by wooden raft from about 129 kilometers off Peru’s coast to Polynesia. But most scholars at that time assumed Asians had voyaged east as early as around 3,500 years ago to relatively close-by western Polynesia, eventually populating eastern Polynesia by around 1,000 years ago without having any contacts with people from South America.”
The study left open the question of who made the monumental Pacific crossing: Polynesians heading east and arriving in Colombia or perhaps Ecuador, or South Americans travelling west.
“I favour the Polynesian theory, since we know that the Polynesians were intentionally exploring the ocean and discovering some of the most distant Pacific islands around exactly the time of contact,” said Stanford University computational geneticist Alexander Ioannidis, lead author of the research published in the journal Nature.
“If the Polynesians reached the Americas, their voyage would likely have been conducted in their double-hulled sailing canoes, which sail using the same principle as a modern catamaran: swift and stable,” Ioannidis added.
This contact explains the mystery of how the sweet potato arrived in Polynesia centuries before European sailors. Ioannidis noted that the sweet potato’s name in many Polynesian languages, kumara, resembles its name in some native Andes languages.
-- with inputs from Reuters