Pedra do Alexandre Forager

The Pedra do Alexandre individual, recovered near Carnaúba dos Dantas in Rio Grande do Norte, dates to roughly 2900–2450 BCE (≈4600 BP). Archaeological data indicates this period falls within the Brazilian Archaic tradition commonly grouped with Lagoa de Encantada hunter-gatherer assemblages across northeastern Brazil. The landscape at the time combined seasonal rivers, patchy gallery forests and Caatinga scrub; this mosaic likely structured mobility and resource use.

Limited evidence suggests the people occupying this area practiced mobile foraging strategies adapted to a semi-arid environment rather than intensive agriculture. Material traces in the region include stone tools and ephemeral camp deposits; shell middens and larger coastal sambaquis are better documented elsewhere in northeastern Brazil but are not attested at Pedra do Alexandre. The genomic signal preserved in this single individual provides a rare biological window into local population history — but with n=1, any narrative of origins must be cautious. Archaeology and genetics together hint at long-standing hunter-gatherer presence in the interior northeast during the Late Holocene, interacting with environmental rhythms and neighboring groups, but further sampling is essential to resolve patterns of continuity, migration, and regional interaction.

The genetic data from the Pedra do Alexandre individual is notable for carrying Y-chromosome haplogroup Q and mitochondrial haplogroup C1b—lineages commonly found across many Native American populations. Haplogroup Q on the paternal line is broadly associated with the initial spread of people across the Americas, while mtDNA C1b is one branch of the deep maternal diversity present among Indigenous American groups. These assignments indicate genetic affinities with pan-American ancestry components preserved in northeastern Brazil and beyond.

However, this dataset consists of a single genome (n=1). Any inference about population structure, migration corridors, or continuity with later Indigenous groups must be considered preliminary. The sample does suggest that by ≈4600 BP, at least some inhabitants of inland Rio Grande do Norte carried continental Native American lineages rather than exclusive local isolation. Comparisons with published Lagoa de Encantada-related genomes hint at regional genetic similarity, but low sample counts prevent robust population-level conclusions. When combined with archaeology — lithic technology, site distributions, and environmental reconstructions — ancient DNA from Pedra do Alexandre opens avenues to test whether northeastern Brazil functioned as a refugium, a corridor, or a melting zone for diverse hunter-gatherer ancestries during the Late Holocene. Increased sampling and careful engagement with descendant communities will be essential to refine these genetic stories.