Ancient mitogenomes from the Southern Pampas of A rgentina reflect local differentiation and limited extra‐regional linkages after rapid initial colonization

MOTTI, JOSEFINA M. B.; PAURO, MAIA; SCABUZZO, CLARA; GARCÍA, ANGELINA; ALDAZÁBAL, VERÓNICA; VECCHI, RODRIGO; BAYÓN, CRISTINA; PASTOR, NICOLÁS; DEMARCHI, DARÍO A.; BRAVI, CLAUDIO M.; REICH, DAVID; CABANA, GRACIELA S.; NORES, RODRIGO

American Journal of Biological Anthropology

Wiley

Lugar: Salt Lake City; Año: 2023 vol. 181 p. 216 - 230

2692-7691

Objective: This study aims to contribute to the recovery of Indigenous evolutionaryhistory in the Southern Pampas region of Argentina through an analysis of ancientcomplete mitochondrial genomes.Materials and Methods: We generated DNA data for nine complete mitogenomesfrom the Southern Pampas, dated to between 2531 and 723 cal BP. In combinationwith previously published ancient mitogenomes from the region and from throughoutSouth America, we documented instances of extra-regional lineage-sharing, and estimated coalescent ages for local lineages using a Bayesian method with tip calibrationsin a phylogenetic analysis.Results: We identified a novel mitochondrial haplogroup, B2b16, and two recentlydefined haplogroups, A2ay and B2ak1, as well as three local haplotypes within founder haplogroups C1b and C1d. We detected lineage-sharing with ancient and contemporary individuals from Central Argentina, but not with ancient or contemporary samples from North Patagonian or Littoral regions of Argentina, despite archeological evidence of cultural interactions with the latter regions. The estimated coalescent age of these shared lineages is 10,000 years BP.Discussion: The history of the human populations in the Southern Pampas is temporally deep, exhibiting long-term continuity of mitogenome lineages. Additionally, the identification of highly localized mtDNA clades accords with a model of relatively rapid initial colonization of South America by Indigenous communities, followed by more local patterns of limited gene flow and genetic drift in various South American regions, including the Pampas.