RESUMO
The inverted triangle shape of South America places Argentina territory as a geographical crossroads between the two principal peopling streams that followed either the Pacific or the Atlantic coasts, which could have then merged in Central Argentina (CA). Although the genetic diversity from this region is therefore crucial to decipher past population movements in South America, its characterization has been overlooked so far. We report 92 modern and 22 ancient mitogenomes spanning a temporal range of 5000 years, which were compared with a large set of previously reported data. Leveraging this dataset representative of the mitochondrial diversity of the subcontinent, we investigate the maternal history of CA populations within a wider geographical context. We describe a large number of novel clades within the mitochondrial DNA tree, thus providing new phylogenetic interpretations for South America. We also identify several local clades of great temporal depth with continuity until the present time, which stem directly from the founder haplotypes, suggesting that they originated in the region and expanded from there. Moreover, the presence of lineages characteristic of other South American regions reveals the existence of gene flow to CA. Finally, we report some lineages with discontinuous distribution across the Americas, which suggest the persistence of relic lineages likely linked to the first population arrivals. The present study represents to date the most exhaustive attempt to elaborate a Native American genetic map from modern and ancient complete mitochondrial genomes in Argentina and provides relevant information about the general process of settlement in South America.
Assuntos
DNA Mitocondrial/genética , Variação Genética , Genética Populacional , Genoma Mitocondrial/genética , Migração Humana , Argentina , DNA Antigo/análise , DNA Mitocondrial/análise , DNA Mitocondrial/classificação , Geografia , Haplótipos , Humanos , Filogenia , Análise de Sequência de DNA , América do Sul , Fatores de TempoRESUMO
In South American societies, domesticated camelids were of great cultural importance and subject to trade and translocation. South American camelids were even found on remote and hard to reach islands, emphasizing their importance to historic and pre-historic South American populations. Isla Mocha, a volcanic island 35 km offshore of Central-South Chile, is an example of such an island. When Dutch and Spanish explorers reached the island in the early 17th century, they found that domesticated camelids called "chilihueque" played a major role in the island's society. The origin and taxonomy of these enigmatic camelids is unclear and controversial. This study aims to resolve this controversy through genetic analyses of Isla Mocha camelid remains dating from pre-Columbian to early historic times. A recent archaeological excavation of site P21-3 on Isla Mocha yielded a number of camelid remains. Three complete mitochondrial genomes were successfully recovered and analysed. Phylogenetic analyses suggest that "chilihueque" was a local term for a domesticated guanaco. Results from phylogeographic analyses are consistent with Isla Mocha camelids being sourced from Southern Chilean guanaco populations. Our data highlights the capability of ancient DNA to answer questions about extinct populations which includes species identity, potential translocation events and origins of founding individuals.
Assuntos
Camelídeos Americanos/genética , Genoma Mitocondrial , Filogenia , Animais , Chile , IlhasAssuntos
Galinhas/genética , DNA Mitocondrial/genética , Isótopos , Datação Radiométrica , Animais , Chile , Dieta , Europa (Continente) , História do Século XV , História Medieval , Humanos , PolinésiaRESUMO
Two issues long debated among Pacific and American prehistorians are (i) whether there was a pre-Columbian introduction of chicken (Gallus gallus) to the Americas and (ii) whether Polynesian contact with South America might be identified archaeologically, through the recovery of remains of unquestionable Polynesian origin. We present a radiocarbon date and an ancient DNA sequence from a single chicken bone recovered from the archaeological site of El Arenal-1, on the Arauco Peninsula, Chile. These results not only provide firm evidence for the pre-Columbian introduction of chickens to the Americas, but strongly suggest that it was a Polynesian introduction.