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Regional patterns of genetic admixture in South America
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Forensic Science International: Genetics Supplement Series 1 (2008) 329–330 www.elsevier.com/locate/FSIGSS
Research article
Regional patterns of genetic admixture in South America N.M.O. Godinho a,b, C.C. Gontijo a, M.E.C.G. Diniz a, G. Falca˜o-Alencar a, G.C. Dalton a,c, C.E.G. Amorim a, R.S.S. Barcelos b,d, M.N. Klautau-Guimara˜es a, S.F. Oliveira a,* a
Depto. GEM, UnB, Brazil Instituto de Criminalı´stica de Goia´s, Brazil c Instituto de Criminalı´stica do Distrito Federal; Brazil d Universidade Cato´lica de Goia´s, Brazil b
Received 1 September 2007; accepted 10 October 2007
Abstract This work aimed to prove that Brazil, Argentina and Colombia, although share similar history, are different in a genetic point of view—by analysis of STR markers. Therefore the use of a genetic databank to South America must be seen with extra care. # 2008 Elsevier Ireland Ltd. All rights reserved. Keywords: Genetic admixture; South America; STRs
1. Introduction The South American population was formed by the admixture of three main ethnic groups: Europeans, Africans and Amerindians. Despite its similar beginning, this peopling process developed in distinct ways. In this paper, we intend to answer whether Argentina, Brazil and Colombia, due to similarities in their histories, present, nowadays, a similar genetic constitution.
2. Materials and methods STR markers (CODIS System—Combined DNA Index System) allelic data were compiled from literature and Internet sites (for the list of references, see [1]) according to the data regional origin in the three countries (Table 1). Admixture analyses were performed using the ADMIX 3 program based on the gene identity method [2]. For that purpose, the weighted mean of the available frequencies for each geographic region under analysis, and for the parental populations [1] were estimated.
* Corresponding author at: Tel.: +55 61 3307 2161; fax: +55 61 3272 4942. E-mail address: [email protected] (S.F. Oliveira). 1875-1768/$ – see front matter # 2008 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.fsigss.2007.10.069
Table 1 European, African and Amerindian parental contributions to the populations of Brazil, Colombia and Argentina and their geographic regions Populations analyzed
Parental group European
African
Amerindian
Brazil Middle-West North Northeast Southeast South Total
0.663 0.019 0.606 0.055 0.667 0.045 0.607 0.025 0.815 0.009 0.643 0.099
0.217 0.015 0.213 0.044 0.234 0.035 0.320 0.017 0.093 0.007 0.252 0.039
0.120 0.008 0.181 0.021 0.100 0.017 0.074 0.021 0.092 0.003 0.105 0.019
Colombia (regions) A B C D Total (without region B)
0.405 0.047 0.116 0.016 0.457 0.042 0.549 0.023 0.487 0.022
0.350 0.037 0.730 0.013 0.137 0.033 0.136 0.018 0.132 0.017
0.245 0.018 0.154 0.006 0.406 0.016 0.415 0.009 0.381 0.008
Argentina Pampa Gran Chaco Mesopotamia Northwest Patagonia Total
0.678 0.050 0.531 0.018 0.630 0.009 0.228 0.14 0.554 0.004 0.589 0.021
0.103 0.039 0.089 0.014 0.064 0.007 0.085 0.013
0.219 0.019 0.379 0.007 0.305 0.003 0.686 0.007 0.446 0.004 0.380 0.008
0.031 0.016
Colombian regions: A, Caribbean Coast; B, North Colombian Pacific Coast and the Caribbean Island of San Andre’s; C, Southwest Andean Region and Vale del Cauca; D, Colombian mountain range of Los Andes and populations settled in the Amazonian Region and Oriental flats (see Ref. [3]).
330
N.M.O. Godinho et al. / Forensic Science International: Genetics Supplement Series 1 (2008) 329–330
3. Results and discussion
Funding source
The European contribution predominates on the three countries (Table 1), and mainly in Brazil. By its turn, the African contribution presents a wide variation (Table 1): it was absent in Patagonia and low in Argentina as a whole; high in Colombian regions A and B; and almost homogenous along the Brazilian territory. The Amerindian contribution, low in Brazil, was substantial both in Colombia and Argentina, reaching values as high as 68.3% in Northwest Argentina. The distribution pattern of Amerindian contribution in these countries points out that, in the regions of major economic development by colonization time, the Amerindian contribution has been smaller than elsewhere, confirming historical and demographic data. Moreover, our data shows that these countries are quite different from a genetic point of view, and, therefore, the use of a unique genetic database as a forensic tool for the entire continent is not possible.
SENASP, SSPGO, CAPES and FINATEC supplied financial support for this project, but without any involvement in the development of this paper.
Acknowledgements We would like to thank SENASP, SSPGO, CAPES and FINATEC for financial support.
Conflict of interest None.
References [1] http://isfg2007.godinho.tripod.com. [2] R. Chakraborty, Gene identity in racial hybrids and estimation of admixture rates, in: Y. Ahuja, J.V. Neel (Eds.), Genetics Microdifferentiation in Human and Other Animal Population, Indian Anthropol Assoc., Delhi University Anthropology Department, Delhi, India, 1985, pp. 171–180. ´ vila, D. Andrade, C. Vergara, M. [3] M. Paredes, A. Galindo, M. Bernala, S. A Rinco´n, R.E. Romero, M. Navarrete, M. Ca´rdenas, J. Ortega, D. Suarez, A. Cifuentes, A. Salas, A. Carracedo, Analysis of the CODIS autosomal STR loci in four main Colombian regions, Forensic Sci. Int. 137 (2003) 67–73.
Forensic Science International: Genetics Supplement Series 1 (2008) 329–330 www.elsevier.com/locate/FSIGSS
Research article
Regional patterns of genetic admixture in South America N.M.O. Godinho a,b, C.C. Gontijo a, M.E.C.G. Diniz a, G. Falca˜o-Alencar a, G.C. Dalton a,c, C.E.G. Amorim a, R.S.S. Barcelos b,d, M.N. Klautau-Guimara˜es a, S.F. Oliveira a,* a
Depto. GEM, UnB, Brazil Instituto de Criminalı´stica de Goia´s, Brazil c Instituto de Criminalı´stica do Distrito Federal; Brazil d Universidade Cato´lica de Goia´s, Brazil b
Received 1 September 2007; accepted 10 October 2007
Abstract This work aimed to prove that Brazil, Argentina and Colombia, although share similar history, are different in a genetic point of view—by analysis of STR markers. Therefore the use of a genetic databank to South America must be seen with extra care. # 2008 Elsevier Ireland Ltd. All rights reserved. Keywords: Genetic admixture; South America; STRs
1. Introduction The South American population was formed by the admixture of three main ethnic groups: Europeans, Africans and Amerindians. Despite its similar beginning, this peopling process developed in distinct ways. In this paper, we intend to answer whether Argentina, Brazil and Colombia, due to similarities in their histories, present, nowadays, a similar genetic constitution.
2. Materials and methods STR markers (CODIS System—Combined DNA Index System) allelic data were compiled from literature and Internet sites (for the list of references, see [1]) according to the data regional origin in the three countries (Table 1). Admixture analyses were performed using the ADMIX 3 program based on the gene identity method [2]. For that purpose, the weighted mean of the available frequencies for each geographic region under analysis, and for the parental populations [1] were estimated.
* Corresponding author at: Tel.: +55 61 3307 2161; fax: +55 61 3272 4942. E-mail address: [email protected] (S.F. Oliveira). 1875-1768/$ – see front matter # 2008 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.fsigss.2007.10.069
Table 1 European, African and Amerindian parental contributions to the populations of Brazil, Colombia and Argentina and their geographic regions Populations analyzed
Parental group European
African
Amerindian
Brazil Middle-West North Northeast Southeast South Total
0.663 0.019 0.606 0.055 0.667 0.045 0.607 0.025 0.815 0.009 0.643 0.099
0.217 0.015 0.213 0.044 0.234 0.035 0.320 0.017 0.093 0.007 0.252 0.039
0.120 0.008 0.181 0.021 0.100 0.017 0.074 0.021 0.092 0.003 0.105 0.019
Colombia (regions) A B C D Total (without region B)
0.405 0.047 0.116 0.016 0.457 0.042 0.549 0.023 0.487 0.022
0.350 0.037 0.730 0.013 0.137 0.033 0.136 0.018 0.132 0.017
0.245 0.018 0.154 0.006 0.406 0.016 0.415 0.009 0.381 0.008
Argentina Pampa Gran Chaco Mesopotamia Northwest Patagonia Total
0.678 0.050 0.531 0.018 0.630 0.009 0.228 0.14 0.554 0.004 0.589 0.021
0.103 0.039 0.089 0.014 0.064 0.007 0.085 0.013
0.219 0.019 0.379 0.007 0.305 0.003 0.686 0.007 0.446 0.004 0.380 0.008
0.031 0.016
Colombian regions: A, Caribbean Coast; B, North Colombian Pacific Coast and the Caribbean Island of San Andre’s; C, Southwest Andean Region and Vale del Cauca; D, Colombian mountain range of Los Andes and populations settled in the Amazonian Region and Oriental flats (see Ref. [3]).
330
N.M.O. Godinho et al. / Forensic Science International: Genetics Supplement Series 1 (2008) 329–330
3. Results and discussion
Funding source
The European contribution predominates on the three countries (Table 1), and mainly in Brazil. By its turn, the African contribution presents a wide variation (Table 1): it was absent in Patagonia and low in Argentina as a whole; high in Colombian regions A and B; and almost homogenous along the Brazilian territory. The Amerindian contribution, low in Brazil, was substantial both in Colombia and Argentina, reaching values as high as 68.3% in Northwest Argentina. The distribution pattern of Amerindian contribution in these countries points out that, in the regions of major economic development by colonization time, the Amerindian contribution has been smaller than elsewhere, confirming historical and demographic data. Moreover, our data shows that these countries are quite different from a genetic point of view, and, therefore, the use of a unique genetic database as a forensic tool for the entire continent is not possible.
SENASP, SSPGO, CAPES and FINATEC supplied financial support for this project, but without any involvement in the development of this paper.
Acknowledgements We would like to thank SENASP, SSPGO, CAPES and FINATEC for financial support.
Conflict of interest None.
References [1] http://isfg2007.godinho.tripod.com. [2] R. Chakraborty, Gene identity in racial hybrids and estimation of admixture rates, in: Y. Ahuja, J.V. Neel (Eds.), Genetics Microdifferentiation in Human and Other Animal Population, Indian Anthropol Assoc., Delhi University Anthropology Department, Delhi, India, 1985, pp. 171–180. ´ vila, D. Andrade, C. Vergara, M. [3] M. Paredes, A. Galindo, M. Bernala, S. A Rinco´n, R.E. Romero, M. Navarrete, M. Ca´rdenas, J. Ortega, D. Suarez, A. Cifuentes, A. Salas, A. Carracedo, Analysis of the CODIS autosomal STR loci in four main Colombian regions, Forensic Sci. Int. 137 (2003) 67–73.