PDA

View Full Version : Admixture in Latin America



cordobesforever
07-03-10, 01:57
Hi, this thread, is about racial admixture in Latin America, to talk of European genes, African and indigenous populations of this region

transmitter
07-03-10, 07:02
No data No Maps......

elghund
07-03-10, 08:07
FTDNA has projects for Mexico, Brazil, Cuba and Puerto Rico

These have Y-DNA and mtDNA lists with haplogroups; you might get a picture from that.

Maciamo
07-03-10, 10:21
Latin America is so ethnically mixed that reliable maps cannot be created. Percentages would vary tremendously from one city neighbourhood to another, between families and between social classes.

In Eurasia regional trends can be observed because no major migration or admixture has happened for over 1000 years and therefore haplogroups have had time to even out around provinces/counties where people traditionally find their spouses.

In Latin America, not only is the admixture between Amerindians, Europeans and Africans barely a few centuries old, but non-Amerindian people also tended to live in big cities from the beginning of colonisation, and cities favour intermarriages between a wide range of potential spouses and a constant rearranging of haplogroups.

Haplogroup frequency tables and maps are normally created based on a person's oldest known ancestor. In Europe this corresponds to about 300 to 700 years ago. This is done to have a clearer view of the haplogroup distribution before the rural exodus of the industrial revolution and emigration to the Americas and Oceania. That's why the haplogroups of Americans (continent-wise) of European descent are already taken into account into European studies. In other words you cannot make a meaningful haplogroup map of modern society because people move around a lot and live mostly in big cities. That's why the only haplogroup maps of the Americas are pre-Columbian.

cordobesforever
07-03-10, 16:56
Yes, I know, I found genetic studies on Latin America, but did not try to haplogroups, if not the frequency of genes Caucasians, Africans and Indians

Wilhelm
07-03-10, 17:01
Argentinians genetics :

http://2.bp.blogspot.com/_Ish7688voT0/Syohlc8Aa8I/AAAAAAAACEQ/zxd3DTSjBGg/s1600/corach.jpg


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.

Wilhelm
07-03-10, 17:07
Others :

http://scienceblogs.com/gnxp/meladmix.png

cordobesforever
09-03-10, 01:20
I was inquiring about some mixtures, and Buenos Aires (Argentina) found a mixture of 80% Caucasian / European, 16% Indian and 4% African: http://www.medicinabuenosaires.com/revistas/vol66-06/2/MEZCLA%20GENICA%20EN%20UNA%20MUESTRA%20POBLACIONAL %20DE%20LA%20CIUDAD%20DE%20BUENOS%20AIRES.pdf

In Santiago (Chile) the mixture is 57% Caucasian / European, 43% indigenous: http://www.fhuce.edu.uy/antrop/cursos/abiol/links/Artics/sans.pdf (pag. 6)

In Mexico City, the mixture is 65% indigenous, 35% Caucasian / European and 5% African: http://redalyc.uaemex.mx/redalyc/pdf/576/57632101.pdf

Genetically, the Latin American countries with greater numbers of genes and European Caucasians, are Argentina and Uruguay.

Now, Wilhelm, I understand what you've posted there, which are those colors that appear in the table above?

Marianne
09-09-10, 14:33
A series from Argentina is currently being broadcasted in Greece, called Patito Feo.

I was very surprised to see that every single actor in the series looks very European to me.

I know that in many Latin American series they tend to use actors that look European although they don't really reprsent the majority of the country's population. In Mexian series I notice that even though the actors have light complexion, they have facial features that are very common in Latin Americans, so one can easily tell they are not Europeans. On the other hand, in the series Patito Feo 90% of the actors look completely European, and especially Spanish.

This got me thinking about the admixture with native Americans in Argentina. After a search I found this thread and the results I read really make sense with what I see in the series. Not only the actors have European facial features but there are also many natural blonds and light eyed ones. Many of them would for sure pass for Greeks, Italians and Spanish in Europe, some even for Germans..