RESUMO
OBJECTIVES: The history of the Caribbean region is marked by numerous and various successive migration waves that resulted in a global blending of African, European, and Amerindian lineages. As the origin and genetic composition of the current population of French Caribbean islands has not been studied to date, we used both mitochondrial DNA and Y-chromosome markers to complete the characterization of the dynamics of admixture in the Guadeloupe archipelago. MATERIALS AND METHODS: We sequenced the mitochondrial hypervariable regions and genotyped mitochondrial and Y-chromosomal single nucleotide polymorphisms (SNPs) of 198 individuals from five localities of the Guadeloupe archipelago. RESULTS: The maternal haplogroups revealed a blend of 85% African lineages (mainly traced to Western, West-Central, and South-Eastern Africa), 12.5% Eurasian lineages, and 0.5% Amerindian lineages. We highlighted disequilibria between European paternal contribution (44%) and European maternal contribution (7%), pointing out an important sexual asymmetry. Finally, the estimated Native American component was strikingly low and supported the near-extinction of native lineages in the region. DISCUSSION: We confirmed that all historically known migratory events indeed left a visible genetic imprint in the contemporary Caribbean populations. The data gathered clearly demonstrated the significant impact of the transatlantic slave trade on the Guadeloupean population's constitution. Altogether, the data in our study confirm that in the Caribbean region, human population variation is correlated with colonial and postcolonial policies and unique island histories.
Assuntos
Cromossomos Humanos Y , DNA Mitocondrial/análise , Migração Humana , Polimorfismo de Nucleotídeo Único , África/etnologia , Europa (Continente)/etnologia , Feminino , Genótipo , Guadalupe , Hereditariedade , Humanos , Masculino , América do Sul/etnologiaRESUMO
OBJECTIVES: The main aim of this work was to contribute to the knowledge of pre-Hispanic genetic variation and population structure among the South-central Andes Area by studying individuals from Quebrada de Humahuaca, North-western (NW) Argentina. MATERIALS AND METHODS: We analyzed 15 autosomal STRs in 19 individuals from several archaeological sites in Quebrada de Humahuaca, belonging to the Regional Developments Period (900-1430 AD). Compiling autosomal, mitochondrial, and Y-chromosome data, we evaluated population structure and differentiation among eight South-central Andean groups from the current territories of NW Argentina and Peru. RESULTS: Autosomal data revealed a structuring of the analyzed populations into two clusters which seemed to represent different temporalities in the Andean pre-Hispanic history: pre-Inca and Inca. All pre-Inca samples fell into the same cluster despite being from the two different territories of NW Argentina and Peru. Also, they were systematically differentiated from the Peruvian Inca group. These results were mostly confirmed by mitochondrial and Y-chromosome analyses. We mainly found a clearly different haplotype composition between clusters. DISCUSSION: Population structure in South America has been mostly studied on current native groups, mainly showing a west-to-east differentiation between the Andean and lowland regions. Here we demonstrated that genetic population differentiation preceded the European contact and might have been more complex than thought, being found within the South-central Andes Area. Moreover, divergence among temporally different populations might be reflecting socio-political changes occurred in the evermore complex pre-Hispanic Andean societies.
Assuntos
DNA Antigo/análise , Indígenas Sul-Americanos/genética , Arqueologia , Feminino , Marcadores Genéticos/genética , Genética Populacional , Humanos , Masculino , Repetições de Microssatélites/genética , Peru , Análise de Sequência de DNA , Dente/químicaRESUMO
Almost all pre-Hispanic societies from Quebrada de Humahuaca (north-western Argentina) buried their defuncts in domestic areas, demonstrating the importance of death and its daily presence among the living. Presumably, the collective graves contained related individuals, a hypothesis that can be tested through the study of ancient DNA. This study analyzes autosomal and uniparental genetic markers in individuals from two archaeological sites in Quebrada de Humahuaca occupied during the Late Formative (1450-1050 BP) and Regional Developments I (1050-700 BP) periods. Mitochondrial and Y-chromosome haplotypes were compared in order to establish possible maternal and paternal relatedness. Genotypes for 15 autosomal STRs were used to calculate pairwise relatedness coefficients and pedigree probabilities. High kinship levels among individuals buried in the same graves were found in both sites. Although only two particular cases were analyzed, these results represent an important contribution to the study of mortuary practices in the region by means of ancient DNA.
Assuntos
Cemitérios , Indígenas Sul-Americanos/genética , Argentina , DNA Mitocondrial/genética , Feminino , Humanos , Masculino , Linhagem , Análise de Sequência de DNARESUMO
This palaeogenetic study focused on the analysis of a late prehispanic Argentinean group from the Humahuaca valley, with the main aim of reconstructing its (micro)evolutionary history. The Humahuaca valley, a natural passageway from the eastern plains to the highlands, was the living environment of Andean societies whose cultural but especially biological diversity is still poorly understood. We analyzed the DNA extracted from 39 individuals who populated this upper valley during the Regional Development period (RDP) (between the 11th and 15th centuries CE), to determine their maternal and paternal genetic ancestry. Some mitochondrial and Y-chromosomal haplotypes specific to the Andean region are consistent with an origin in the highlands of Central Andes. On the other hand, a significant genetic affinity with contemporary admixed communities of the Chaco area was detected. Expectedly, recent demographic events, such as the expansion of the Inca Empire or the European colonization, have changed the original mitochondrial gene pool of the ancient Humahuaca Valley community. Finally, we identified a particular geographical organization of the prehispanic populations of Northwestern Argentina. Our results suggest that the communities of the region were divided between two different spheres of interaction, which is consistent with assumptions made by means of craniometric traits.
Assuntos
Evolução Biológica , Cromossomos Humanos Y/genética , DNA Mitocondrial/genética , Fósseis , Variação Genética , Indígenas Sul-Americanos/genética , Arqueologia/métodos , Argentina , Sequência de Bases , Genética Populacional , Haplótipos/genética , História Medieval , Humanos , Dados de Sequência Molecular , Análise de Sequência de DNARESUMO
Ancient DNA recovered from 21 individuals excavated from burial sites in the Pampa Grande (PG) region (Salta province) of North-Western Argentina (NWA) was analyzed using various genetic markers (mitochondrial DNA, autosomal STRs, and Y chromosomal STRs). The results were compared to ancient and modern DNA from various populations in the Andean and North Argentinean regions, with the aim of establishing their relationships with PG. The mitochondrial haplogroup frequencies described (11% A, 47% B, and 42% D) presented values comparable to those found for the ancient Andean populations from Peru and San Pedro de Atacama. On the other hand, mitochondrial and Y chromosomal haplotypes were specific to PG, as they did not match any other of the South American populations studied. The described genetic diversity indicates homogeneity in the genetic structure of the ancient Andean populations, which was probably facilitated by the intense exchange network in the Andean zone, in particular among Tiwanaku, San Pedro de Atacama, and NWA. The discovery of haplotypes unique to PG could be due to a loss of genetic diversity caused by recent events affecting the autochthonous populations (establishment of the Inca Empire in the region, colonization by the Europeans).