Full text in pdf format

Genetic structure and demography of the human population of Óbidos, in the Brazilian Amazon

João Farias Guerreiro; Ândrea Kely Campos Ribeiro dos Santos; Eduardo José Melo dos Santos; Isaura Maria Vieira Cayres; Sidney Emanuel Batista dos Santos

Laboratório de Genética Humana e Médica, Departamento de Patologia, Centro de Ciências Biológicas, Universidade Federal do Pará, 66075-900 Belém, PA, Brasil. Send correspondence to J.F.G.

ABSTRACT

Migratory parameters and the genetics of thirteen blood systems were studied in a sample of 250 individuals from the trihybrid population of Óbidos, State of Pará, Brazil. The dispersion indices indicate a low population mobility; the locally born individuals account for 80% of the sample studied, and 88% of the immigrants were born in the State of Pará. The phenotype distribution presented some differences when compared to those reported for other Amazonian populations (Oriximiná, Parintins, Coari, Belém and Manaus). The average heterozygosity (H) was estimated as 0.200 (S.E. 0.055), the mean number of alleles per locus at 2.000 (S.E. 0.260), and the percentage of polymorphic loci at 84.6%. In terms of racial admixture (38% White, 52% Indian and 10% Black), Óbidos presents values similar to those observed for the population of Parintins, State of Amazonas, with a low Black and a high Indian contribution.

Keywords: genetic structure; demography; human population; Óbidos; Brazilian Amazon.

REFERENCES

Ayres, M., Salzano, F.M., Franco, M.II.L.P. and Barros, R.M.S. (1976). The association of blood groups, ABH secretion, haptoglobins and hemoglobins with filariasis. Hum. Hered. 26: 105-109.

Carneiro, E. (1980). A Conquista da Amazônia. Civilização Brasileira, Rio de Janeiro, pp.168.

Corvelo, T.C.O. and Salzano, F.M. (1984). New genetic data from an Amazonian town. Interciencia 9: 236-238.

Guerreiro, J.F. and Chautard-Freire Maia, E.A. (1984). Studies on serum cholinesterase (CIIE1 locus) in a sample from Northern Brazil. Rev. Brasil. Genet. 4: 717-725.

Guerreiro, J.F. and Chautard-FrEirc-Maia, E.A. (1988). ABO and Rh blood groups, migration and estimates of racial admixture for the population of Belém, State of Pará, Brazil. Rev Brasil. Genet. 11: 171-186.

Hamel, M.L., Salzano, F.M. and Freitas, M.J.M. (1984). The Gm polymorphism and racial admixture in six Amazonian populations. J. Hum. Evol. 13: M7-529.

Krieger, H., Morton, N.E., Mi., M.P., Azevedo, E., Freire-Maia, A. and Yasuda, N. (1965). Racial admixture in northeastern Brazil. Ann. Hum. Genet. 29: 113-125.

Nei, M. (1987). Molecular Evolutionary Genetics. Columbia University Press, New York, pp.176-184.

Reed, T.E. and Schutt, W.J. (1968). A general maximum likelihood estimation program. Am. J. Hum. Genet. 20: 579-580.

Rosa, V.L., Salzano, F.M., Franco, M.H.L.P. and Freitas, M.J.M. (1984). Blood genetic studies in five Amazonian populations. Rev. Brasil. Genet. 7: 569-582.

Santos, S.E.B., Salzano, F.M., Franco, M.H.L.P. and Freitas, M.J.M. (1983). Mobility, genetic markers, susceptibility to malaria and race admixture in Manaus, Brazil. J. Hum. Evol. 12: 373-381.

Santos, S.F.B., Guerreiro, J.F., Salzano, F.M., Weimer, T.A., Hutz, M.H. and Franco, M.H.L.P. (1987). Mobility, blood genetic traits and race admixture in the Amazonian population of Oriximiná. Rev. Brasil. Genet. 10: 745-759.

Schneider, H., Ouerreiro, J.F., Santos, S.E.B., Weimer, T.A., Schneider, M.P.C. and Salzano, F.M. (1987). Isolate breakdown in Amazonia: the blacks of the Trombetas river. Rev. Brasil. Genet. 3: 565-574.

Schüler, L., Salzano, F.M., Franco, M.H.L.P., Freitas, M.J.M., Mestriner, M.A. and Simões, A.L. (1982). Demographic and blood characteristics in an Amazonian population. J. Hum. Evol. 11: 549-558.