Argentinians genetics :
From : http://dienekes.blogspot.com/2009/12/new-comprehensive-study-on-continental.html
An interesting find from the study:
Whereas 96% of the individuals with European surnames carried European Y-chromosomes, 50% of the samples from individuals with Amerindian surnames had
European Y chromosomes.
The combined use of Y-chromosome, mtDNA, and autosomal markers in a sample gives us a rare opportunity to see how well inferences of ancestry from uniparental markers matches with that from autosomal ones:
European ancestry in mtDNA (44.3%) and Y-chromosome (94.1%) gives an estimate of 69.2%, compared to 78.6% for autosomal markers. Native S. American in mtDNA (53.7%) and Y-chromosome (4.9%) gives an estimate of 29.3%, compared to 17.28% for autosomal markers. Finally, African mtDNA (2%) and Y-chromosomes (0.9%) gives an estimate of 1.45% compared to 4.15% for the autosomal markers.
It is difficult to guess how much of the difference is due to the small number of markers used, how much is due to the choice of parental populations for the admixture estimate (which cannot match perfectly the actual parental populations), and how much is due to the inclusion of pigmentation-related markers which have substantial inter-continental differences, but may have shifted frequencies due to social selection.
Annals of Human Genetics doi:10.1111/j.1469-1809.2009.00556.x
Inferring Continental Ancestry of Argentineans from Autosomal, Y-Chromosomal and Mitochondrial DNA
Daniel Corach et al.
Abstract
We investigated the bio-geographic ancestry of Argentineans, and quantified their genetic admixture, analyzing 246 unrelated male individuals from eight provinces of three Argentinean regions using ancestry-sensitive DNA markers (ASDM) from autosomal, Y and mitochondrial chromosomes. Our results demonstrate that European, Native American and African ancestry components were detectable in the contemporary Argentineans, the amounts depending on the genetic system applied, exhibiting large inter-individual heterogeneity. Argentineans carried a large fraction of European genetic heritage in their Y-chromosomal (94.1%) and autosomal (78.5%) DNA, but their mitochondrial gene pool is mostly of Native American ancestry (53.7%); instead, African heritage was small in all three genetic systems (less than 4%). Population substructure in Argentina considering the eight sampled provinces was very small based on autosomal (0.92% of total variation was between provincial groups, p = 0.005) and mtDNA (1.77%, p = 0.005) data (none with NRY data), and all three genetic systems revealed no substructure when clustering the provinces into the three geographic regions to which they belong. The complex genetic ancestry picture detected in Argentineans underscores the need to apply ASDM from all three genetic systems to infer geographic origins and genetic admixture. This applies to all worldwide areas where people with different continental ancestry live geographically close together.