Peopling of Oceania: Clarifying an Initial Settlement Horizon in the Mariana Islands at 1500 Bc

Abstract

Radiocarbon (14C) has been instrumental in clarifying how people came to inhabit the expanse of Pacific Oceania, now supporting an “incremental growth model” that shows a number of long-distance sea-crossing migrations over the last few millennia. A crucial step in this narrative involved the initial settlement of the remote-distance Oceanic region, in the case of the Mariana Islands around 1500 BC. The Marianas case can be demonstrated through delineation of stratigraphic layers, dating of individual points or features within those layers, redundant dating of samples in secure contexts, localized and taxon-specific corrections for marine samples, and cross-constraining dating of superimposed layer sequences. Based on the technical and methodological lessons from the Marianas example, the further steps of the incremental growth model will continue to be refined across Pacific Oceania. Many of these issues may be relevant for broader research of ancient settlement horizons in other regions.

Ancient DNA from Guam and the Peopling of the Pacific

“…However, the TreeMix and AdmixtureBayes results (Figure 5) do not support this scenario, nor does the linguistic and archaeological evidence. In particular, the earliest pottery in the Marianas, dating to around 3.5 kya (2, 42), likely predates the oldest Lapita sites to the east of New Guinea, dated to not more than 3.3 kya (4). Yet the pottery, fine shell ornaments, and other cultural objects in the Marianas dating to 3.5 kya are quite distinct from the Lapita tradition, and instead can be linked to material markers in the Philippines that date to 3.8-3.5 kya (18, 29, 61), thus supporting movement from the Philippines to the Marianas.…”

“…Consisting of 15 islands (of which Guam is the largest and southernmost) stretching across some 750 km of sea, the archipelago is located ~2500 km east of the Philippines and ~2200 km north of New Guinea (Figure 1). The earliest archaeological sites date to around 3.5 thousand years ago (kya) (2), and paleoenvironmental evidence suggests even older occupation, starting around 4.3 kya (3). Thus, the first human presence in the Marianas was at least contemporaneous with, and possibly even earlier than, the earliest Lapita sites in Island Melanesia and western Polynesia that date to after 3.3 kya (4) and are associated with the ancestors of Polynesians.…”

Ancient DNA from Guam and the peopling of the Pacific

“…5 ) do not support this scenario, nor does the linguistic and archaeological evidence. In particular, the earliest pottery in the Marianas, dating to around 3.5 kya ( 3 , 43 ), likely predates the oldest Lapita sites to the east of New Guinea, dated to not more than 3.3 kya ( 5 ). Yet the pottery, fine shell ornaments, and other cultural objects in the Marianas dating to 3.5 kya are quite distinct from the Lapita tradition, and instead can be linked to material markers in the Philippines that date to 3.8 to 3.5 kya ( 19 , 30 , 62 ), thus supporting movement from the Philippines to the Marianas.…”

“…1 ). The earliest archaeological sites date to around 3.5 thousand y ago (kya) ( 3 ), and paleoenvironmental evidence suggests even older occupation, starting around 4.3 kya ( 4 ). Thus, the first human presence in the Marianas was at least contemporaneous with, and possibly even earlier than, the earliest Lapita sites in Island Melanesia and western Polynesia that date to after 3.3 kya ( 5 ) and are associated with the ancestors of Polynesians.…”

Clarifying the Age of Initial Settlement Horizon in the Mariana Islands and the Impact of Hard Water: A Response to Carson (2020)

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This paper is a response to criticism by Carson (2020) concerning the age of the Unai Bapot archaeological site in the Mariana Islands. Of specific contention are supposed errors in the marine radiocarbon ( 14 C) research reported by Petchey et al (2017).

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