Brief communication: Admixture analysis with forensic microsatellites in Minas Gerais, Brazil: The ongoing evolution of the capital and of an African‐derived community

Abstract

We report the estimated allele frequencies for 13 and 14 microsatellite loci in two populations of Minas Gerais, Brazil as follows: Belo Horizonte (the capital) and Marinhos (an African-derived community). Analysis of the African, Amerindian, and European genetic contributions to both populations, together with historical information, revealed distinct differences between the two populations. Estimates for Belo Horizonte revealed a higher-European (66%) than African (32%) contribution, and a minimal Amerindian contribution. These results are consistent with the peopling of the city mainly by people from the Minas Gerais hinterland, a people highly admixed but with more European ancestry. Estimates for Marinhos confirmed the high-African component of the population. However, a temporal analysis of two datasets-CURRENT (representing the population living in Marinhos today) and ORIGINAL (representing families, who have lived in Marinhos since the onset of the 20th century),-identified a diminishing of the population's African ancestry from 92% in the ORIGINAL group to 67% in the CURRENT group. This change is here interpreted as a consequence of the growing migration into the village of people with more European ancestry and subsequent admixture with the local population.

Brazilian quilombos: A repository of Amerindian alleles

“…Even though an Amerindian genetic component has been described repeatedly in quilombos, mainly due to the relationship between these groups and native tribes (Bortolini et al, 1999;Luizon et al, 2008;Scliar et al, 2009;Amorim et al, 2011aAmorim et al, , 2012, we found that Amerindian contributions observed in SAG and STI are much higher than those described in other Brazilian quilombos previously studied. Specifically, we estimated Amerindian contributions for SAG (42%) and STI (40.7%) significantly higher than the highest Amerindian contributions previously described (20%) (Amorim et al, 2011a, b;Palha et al, 2011).…”

“…However, we observed distinct genetic ancestry patterns even between the two quilombo populations we studied. Among the SAG, a quilombo settled in an area also co-occupied by Amerindians, we found that the parental admixture estimate was higher for the Amerindian than for the African component, unlike what we expected given the examples from other quilombos found in the literature (Bortolini et al, 1999;Luizon et al, 2008;Scliar et al, 2009;Amorim et al, 2011a), and yet consistent with its history and geographic location. On the other hand, we found that the admixture estimate in STI shows a higher African contribution than an Amerindian one.…”

“…Quilombos have been discovered all over the Brazilian territory, except in the northern states of Acre and Roraima (Fundação Cultural Palmares-http://palmares.gov.br). Despite variable degrees of isolation, people of different ancestries inhabited most quilombos (Karasch, 1996;Reis and Gomes, 1996;Ribeiro, 2006), making their genetic constitution quite heterogeneous and complex (Bortolini et al, 1999;Luizon et al, 2008;Scliar et al, 2009;Palha et al, 2011;Ribeiro et al, 2011;Amorim et al, 2011a).…”

“…Population genetics has been used as a tool to understand the quilombos' history, owing to the genetic diversity present in these communities and the lack of consistent or comprehensive documentation on their existence (Karash, 1996;Reis and Gomes, 1996;Bortolini et al, 1999;Luizon et al, 2008;Scliar et al, 2009;Amorim et al, 2011a;Palha et al, 2011;Ribeiro et al, 2011;Amorim et al, 2012). Genetic studies have shown that the quilombos have a high African contribution and variable contributions from Amerindians and Europeans (Bortolini et al, 1999;Ribeiro-dos-Santos et al, 2002;Oliveira et al, 2006;Barbosa et al, 2006;Carvalho et al, 2008;Santos et al, 2010;Assis et al, 2011;Palha et al, 2011;Amorim et al, 2011a;, and some of these communities, such as Mocambo (Amorim et al, 2011a), contain a particularly high proportion of Amerindian genes compared with other populations.…”

Interethnic admixture and the evolution of Latin American populations

“…Amorim et al (2011); 8. Scliar et al (2009); 9. Kimura et al (2013); a subset of these communities was also studied for two Alu insertions, and the values used to estimate parental contributions (Cotrim et al , 2004), but the results obtained showed inconsistencies among the populations and were not considered; 10.…”