Admixed Colombians

The American Journal of Human Biology has an interesting article by Salas et. al. (2008) on admixture in Colombian populations at least from the maternal perspective. They investigate mtDNA sequence variation in 185 Colombians that define themselves as "mestizo", "mulatto", and "afro-Colombian" what they find is based on mtDNA, "mestizo" are primarily Native American (97%), and "mulatto" (~81% haplogroup L) and "afro-Colombian" (72% L and 23% Native American) are primarily from Africa. They conclude that self-reported ancestry is not a reliable source of information. Their concern is that if a forensic scientists believes a population is genetically homogeneous than they will increase the likelihood of type I statistical error.

One thing I wasn't sure about was this quote

"Haplotype C16111T C16223T C16290T G16319A T16362C is observed at high frequency in the Haida from Queen Charlotte Islands (North America), but it is also present in the Xavante Brazilians (Ward et al., 1996) or in the Kuna from Panama (Batista et al., 1995)" Salas et al. 1997

isn't this haplogroup A2 and common throughout the Americas as it also found in the Embera (Kolman and Bermingham 1997), the Ache (Schmidt et al. 2004) among others. The Xavante are characterized by a high frequency of haplogroup B as are the Ache.

I however found this quote incredibly insightful

"Undetected population stratification has an important bearing in forensic casework if an expert consulting a database wrongly assumes that the populations (lacking correctly defined genetic ancestry) are genetically homogenous." (Salas et al. 1997)

References Cited

Batista O,Kolman CJ,Bermingham E. 1995. Mitochondrial DNA diversity in the Kuna Amerinds of Panama. Hum Mol Genet 4: 921-929.

Kolman CJ, Bermingham E. 1997. Mitochondrial and nuclear DNA diversity in the Chocó and Chibcha Amerinds of Panamá. Genetics. 1997 Nov;147(3):1289-302.

Salas A. , A. Acosta , V. Álvarez-Iglesias , M. Cerezo , C. Phillips , M. V. Lareu, Á. Carracedo. (2008) "The mtDNA ancestry of admixed Colombian populations" Am. J. Hum. Bio. Early View.

Schmitt R, Bonatto SL, Freitas LB, Muschner VC, Hill K, Hurtado AM, Salzano FM. 2004. Extremely limited mitochondrial DNA variability among the Aché Natives of Paraguay. Ann Hum Biol. 2004 Jan-Feb;31(1):87-94.

Ward RH,Salzano FM,Bonatto SL,Hutz MH,Coimbra CEA,Santos RV. 1996. Mitochondrial DNA polymorphism in 3 Brazilian Indian tribes. Am J Hum Biol 8: 317-323.