In new research, researchers from the Max Planck Institute for Evolutionary Anthropology, Australian National University and the University of Guam analyzed ancient DNA from two humans who lived on Guam 2,200 years ago and found that their ancestry is linked to the Philippines. Moreover, they are closely related to ancient humans from Vanuatu and Tonga, suggesting that the early Mariana Islanders may have been involved in the colonization of Polynesia.
Tahitian warrior dugouts from ‘Le Costume Ancien et Moderne’ by Giulio Ferrario, Milan, between 1816 and 1827.
Humans reached the Mariana Islands in the western Pacific by 3,500 years ago, contemporaneous with or even earlier than the initial peopling of Polynesia.
They crossed more than 2,000 km (1,243 miles) of open ocean to get there, whereas voyages of similar length did not occur anywhere else until more than 2,000 years later.
There is debate over where people came from to get to the Marianas, with various lines of evidence pointing to the Philippines, Indonesia, New Guinea, or the Bismarck Archipelago.
“We know more about the settlement of Polynesia than we do about the settlement of the Mariana Islands,” said Dr. Irina Pugach, a researcher in the Department of Evolutionary Genetics at the Max Planck Institute for Evolutionary Anthropology.
Dr. Pugach and her colleagues from Germany, Australia and Guam wanted to find out where people came from to get to the Marianas and how the ancestors of the present Mariana Islanders, the Chamorro, might be related to Polynesians.
To address these questions, the researchers obtained ancient DNA from two skeletons from the Ritidian Beach Cave site in northern Guam, dating to around 2,200 years ago.
“We found that the ancestry of these ancient skeletons is linked to the Philippines,” Dr. Pugach said.
“These findings strengthen the picture that has emerged from linguistic and archaeological studies, pointing to an Island Southeast Asia origin for the first settlers of the Marianas,” said co-author Dr. Mike Carson, an archaeologist in the Micronesian Area Research Center at the University of Guam.
“We also find a close link between the ancient Guam skeletons and early Lapita individuals from Vanuatu and Tonga in the Western Pacific region,” Dr. Pugach said.
“This suggests that the Marianas and Polynesia may have been colonized from the same source population, and raises the possibility that the Marianas played a role in the eventual settlement of Polynesia.”
While the new results provide interesting new insights, they are based on only two skeletons that date from around 1,400 years after the first human settlement in Guam.
“The peopling of Guam and the settlement of such remote archipelagos in Oceania needs further investigation,” said senior author Dr. Mark Stoneking, a researcher in the Department of Evolutionary Genetics at the Max Planck Institute for Evolutionary Anthropology.
The results appear in the Proceedings of the National Academy of Science.
_____
Irina Pugach et al. 2021. Ancient DNA from Guam and the peopling of the Pacific. PNAS 118 (1): e2022112118; doi: 10.1073/pnas.2022112118
