Latte People of Guam

The Latte era is both architectural and maritime: a horizon defined by paired stone pillars (latte) and intensifying settlement of coastal terraces. Archaeological data from Guam—most notably graves and midden deposits at the Naton Beach Site—show cultural continuity across centuries. While the classic latte monuments commonly dated to the later first millennium CE signal a visible change in communal expression, the genetic record in this dataset reaches back to 262 CE, hinting at deeper demographic roots before monument construction became widespread.

Limited evidence suggests that the people who built and used latte structures were part of long-distance networks stretching into Island Southeast Asia. Material culture—ceramics, shell tools, and imported stone—implies exchange and mobility. At Naton Beach, stratified deposits preserve a sequence of coastal lifeways: early fishing and shellfish gathering, evolving into more complex settlement patterns. Archaeology indicates the Latte Culture of Guam did not appear from nowhere; rather, it emerged from island communities adapting maritime skills, new social architecture, and regional contacts across centuries. However, the picture remains incomplete: preservation in tropical soils is variable, and many island sites have yet to be sampled for ancient DNA.

This dataset includes genetic data from 75 individuals recovered primarily at the Naton Beach Site, spanning 262–1655 CE—one of the larger ancient samples sets from Guam to date. Maternal lineages are dominated by mtDNA haplogroup E2a (54 individuals), with additional E and E2 sublineages (10 and 9 individuals respectively). These E-lineages are characteristic of Island Southeast Asia and parts of Near Oceania, and their prevalence here supports archaeological indications of maternal continuity and strong ties to regional populations.

Notably, common Y-DNA haplogroups are not reported in the provided dataset, so paternal-biased migration or male-mediated admixture cannot be directly assessed. The large mtDNA sample size gives confidence in statements about maternal ancestry, but geographic sampling is concentrated at a single site; therefore, population structure across Guam and the wider Marianas may be underrepresented. Ancient DNA preservation in tropical contexts is challenging, and while 75 samples make this a robust maternal dataset, interpretations should remain cautious about broader demographic processes such as migration pulses, gene flow from Polynesia, or later colonial admixture without complementary genome-wide and Y-chromosome data.