16 research outputs found
Demographic History of Indigenous Populations in Mesoamerica Based on mtDNA Sequence Data
The genetic characterization of Native American groups provides insights into their history and demographic events. We sequenced the mitochondrial D-loop region (control region) of 520 samples from eight Mexican indigenous groups. In addition to an analysis of the genetic diversity, structure and genetic relationship between 28 Native American populations, we applied Bayesian skyline methodology for a deeper insight into the history of Mesoamerica. AMOVA tests applying cultural, linguistic and geographic criteria were performed. MDS plots showed a central cluster of Oaxaca and Maya populations, whereas those from the North and West were located on the periphery. Demographic reconstruction indicates higher values of the effective number of breeding females (Nef) in Central Mesoamerica during the Preclassic period, whereas this pattern moves toward the Classic period for groups in the North and West. Conversely, Nef minimum values are distributed either in the Lithic period (i.e. founder effects) or in recent periods (i.e. population declines). The Mesomerican regions showed differences in population fluctuation as indicated by the maximum Inter-Generational Rate (IGRmax): i) Center-South from the lithic period until the Preclassic; ii) West from the beginning of the Preclassic period until early Classic; iii) North characterized by a wide range of temporal variation from the Lithic to the Preclassic. Our findings are consistent with the genetic variations observed between central, South and Southeast Mesoamerica and the North-West region that are related to differences in genetic drift, structure, and temporal survival strategies (agriculture versus hunter-gathering, respectively). Interestingly, although the European contact had a major negative demographic impact, we detect a previous decline in Mesoamerica that had begun a few hundred years before
Populations analyzed.
<p>Geographical distribution of populations analyzed (in bold) and those used for comparison purposes. Pie charts show haplogroup frequencies. Red lines indicate genetic barrier intensity and green lines the Monmonier geometric traces used to construct the barriers.</p
Theta estimators of eight indigenous populations from Mesoamerica and Aridoamerica.
<p>Theta estimators of eight indigenous populations from Mesoamerica and Aridoamerica.</p
Sequence diversity indices for mtDNA lineages in the control region (16024-576) in eight indigenous populations.
*<p>level of significance of 0.05.</p><p>N, sample size; K, number of different sequences; S, number of polymorphic sites; Ĥ, sequence diversity; π, nucleotide diversity; θ, mean number of pairwise differences between sequences; D, Tajima test of selective neutrality (sd represents the standard deviation).</p
Multidimensional scaling based on the F<sub>ST</sub> distances of eight indigenous populations from Mesoamerica and Aridoamerica (Stress = 0.097).
<p>Multidimensional scaling based on the F<sub>ST</sub> distances of eight indigenous populations from Mesoamerica and Aridoamerica (Stress = 0.097).</p
Skyline plot for the 28 populations grouped in the five cultural regions.
<p>North, West, Central, Oaxaca and Maya.</p
Geographical and cultural information from the 28 Native American populations included in this study.
<p>Geographical and cultural information from the 28 Native American populations included in this study.</p
Hgs frequencies (%) for the eight Native Mexican populations according to the complete mtDNA control region.
<p>Hgs frequencies (%) for the eight Native Mexican populations according to the complete mtDNA control region.</p