Genetics, the myth-buster? The case of Argentina

As I have noted before one of the consequences of genomic analysis techniques becoming relatively cheap and accessible is that they are now viable tools toward exploring a host of fundamentally non-genetic questions. That is, instead of exploring the dynamics of evolutionary biology, they can be used to shed light upon other sorts of dynamics. Sometimes the questions are fuzzy and the techniques can be laborious; e.g., the extraction and analysis of ancient DNA and their subsequent insertion into an explanatory framework where the non-genetic data are patchy. On other occasions, the interpretations are easier.

Consider the demographics of Argentina:

Argentina is a melting pot of different peoples, both autochthonous and immigrants. Citizens of European descent make up the great majority of the population, with estimates varying from white 89.7% to 97% of the total population. The last national census, based on self-ascription, indicated a similar figure.

As a point of comparison, the United States of America is 74% white in terms of self-identified race. In other words, Argentina is a nation with a self-perception of more European ancestry than that of the United States! Argentines consider themselves to be a fundamentally European derived people, in other words, they're a settler society like the United States, Australia or New Zealand. This is in contrast to the melting-point mythologies which are dominant in places such as Mexico or, a lesser extent, Brazil.1 But what do the genes say? Well:

A study conducted by Argentine, Swedish and North American institutions, established that the genetic average structure of the Argentine population, contains 79.9% of European contribution, whereas the Amerindian admixture, though not fully visible in physical appearance, was estimated to be present in a high percentage of the population, close to 56% on either paternal or maternal lineages, of which just 10% were shown to have Amerindian ancestors on both lineages.

This study, Argentine population genetic structure: large variance in Amerindian contribution, has more detail:

Argentine population genetic structure was examined using a set of 78 ancestry informative markers (AIMs) to assess the contributions of European, Amerindian, and African ancestry in 94 individuals members of this population. Using the Bayesian clustering algorithm STRUCTURE, the mean European contribution was 78%, the Amerindian contribution was 19.4%, and the African contribution was 2.5%. Similar results were found using weighted least mean square method: European, 80.2%; Amerindian, 18.1%; and African, 1.7%. Consistent with previous studies the current results showed very few individuals (four of 94) with greater than 10% African admixture. Notably, when individual admixture was examined, the Amerindian and European admixture showed a very large variance and individual Amerindian contribution ranged from 1.5 to 84.5% in the 94 individual Argentine subjects. These results indicate that admixture must be considered when clinical epidemiology or case control genetic analyses are studied in this population. Moreover, the current study provides a set of informative SNPs that can be used to ascertain or control for this potentially hidden stratification. In addition, the large variance in admixture proportions in individual Argentine subjects shown by this study suggests that this population is appropriate for future admixture mapping studies.

Additionally, as in most Latin American populations, the admixture exhibits a strong sex bias, it seems that maternal lineages (mtDNA) are much more Amerindian than paternal (Y) lineages. The results above use autosomal markers, that is, examining points across the whole genome, so it is not surprising that the Amerindian fraction is far lower than what mtDNA would show.

So what does the genetics tell us in combination with the social data? Individuals will admit or identify to non-European ancestry only when it is visible, because white identity is normatively preferred (in the United States the proportion claiming Native American ancestry has increased in direct relation to the rehabilitation and romanticization of Native people).1 If one assumes that only with an ancestral proportion around 1/3 can one not deny non-European ancestry (at least on average), then the vast majority of Argentines with a significant proportion of non-European ancestry (on the order of 5% or greater) could likely pass as white.2

The bigger picture of what this tells us is that identity is a synthesis of various factors. The Argentine identity is shaped by social considerations; the self-perception that Argentina is a European society, the tacit assumption that to be white is to be a normal Argentine, and so forth. But these preferences and social dynamics lay atop genetic realities mediated through phenotypic perceptions. In plain English, if Argentina had a more balanced Amerindian and European genetic contribution a straightforward self-image as a European settle society would be implausible, too many characteristics which would identify a strong non-European genetic ancestral component would be extant within the population. As it is, since Argentines are mostly European in ancestry the non-European signal, which is easily discernible at the genetic level, is also easily masked. This is a function of the way our cognitive engine interprets traits and engages in categorization. Genetic inheritance is a discrete process, DNA information is encoded along base pairs, but because of the incredible number of points we naturally tend to engage in a blending fallacy in our everyday relations. In terms of phenotype our classes are coarse, and instead of engaging in some sort of complex statistical inference we simply utilize rough & ready heuristics. We bin people into their categories, and we reconceptualize any more finely graded variation to conform to our small set of distinct classes.

1 - Immigrant groups such as Germans and Japanese seem to have preserved a greater amount of cultural distinctiveness in Brazil than in Mexico, where a mestizo identity is dominant even though the conventional racial caste system with Europeans on top, mestizos in the middle and the Indians on the bottom still persists nevertheless.

2 - The conflation between white and European here is problematic. Though most Argentines are of Italian, Spanish or Northern European ancestry, a significant minority of Arabs exists. In fact, there was a recent president of Syrian ancestry. Since Levantine Arabs can usually pass as Southern European I don't think that they would be assumed to be non-white, though their "Turkish" identity is noted in most Latin American countries (both Shakira and Salma Hayek have Arab ancestry).


More like this

One of the problems with human genetics where it resembles economics are the ethical issues involved in experimentation. Luckily for science, but unluckily for individuals, medicine offers many "natural experiments." But in the area of population genetics and history analyses of pedigrees or…
Dienekes points me to a new paper, Demographic history of Canary Islands male gene-pool: replacement of native lineages by European (PDF). Here are the results: Autochthonous (E-M81) and prominent (E-M78 and J-M267) Berber Y-chromosome lineages were detected in the indigenous remains, confirming a…
Earlier this week I posted a link to new research on the genomics of Mexican populations and the impact of selective evolutionary pressures within the last 500 years. I also pointed to the fact that despite Argentina's self-conception as a European settler nation, a non-trivial Amerindian…
Comparing Genetic Ancestry and Self-Described Race in African Americans Born in the United States and in Africa (H/T Yann): Genetic association studies can be used to identify factors that may contribute to disparities in disease evident across different racial and ethnic populations. However, such…

In most Latin American countries, the Arab population is made up mostly of Palestinian or Lebanese Christians. This group tends to be affluent and has disproportionate political and economic influence.
Besides Argentina, Ecuador and El Salvador have also had presidents of Arab descent. I am not sure whether they were of wholly Arab descent(like Menem)* or partly mestizo.

*Menem, unlike most of the better known "Turcos", came from a Muslim family and (allegedly) converted to Christianity prior to assuming the presidency.

In most Latin American countries, the Arab population is made up mostly of Palestinian or Lebanese Christians. This group tends to be affluent and has disproportionate political and economic influence.

brazil has more people of lebanese origin by some estimates than lebanon.

*Menem, unlike most of the better known "Turcos", came from a Muslim family and (allegedly) converted to Christianity prior to assuming the presidency.

well, he had to convert to be president cuz of the constitution. but yeah, he probably remains a crypto-muslim, his wife and rest of his family remained in that religion.

I would think that there is a difference between Buenos Aires and the rest of the country. BA has lots of descendants of Italian immigrants who I doubt have much Indian ancestry.

In Trinidad, which is, admittedly, not Latin American, Syrian/Lebanese were not considered white until a generation or so ago. But then, Portuguese weren't "real white" either, nor, I suspect, were Corsicans (although they were a smaller element).

The term 'arabe' or 'hispano-arabe' was/is used to describe Syrio-Lebanese in Argentina but this "whiteness concept" is at odds with mestizaje, the primal raison d'etre of Latin America. The Syrio-lebanese of the 1900's were called Turcos (they weren't Turks) because Turkey was in control of the Arab World (had been for over 300 years). This is similar to USA where mixed blood people are called Spanish, which they are not but it is just a convenient terminology.
It is like saying Tamizgh (Berber) are Arab because they speak Arabic but they are really Arabized Berbers!

The European pool in Argentina is far greater (than USA) because the natives Americans were already killed and Africans were small although in some sources, they were usually conscripted to fight (Paraguay-Uruguay Wars) and the rest of mulatos/mestizos were absorbed into the great European immigration.

Trinidad, as part of the Caribbean (under the control of Gran Colombia) at the time received a cedula of population from Don Antonio Cedeno that allowed French Creoles (criollos) under a cedula of population to enter the country due to the slave rebellions in Haiti.
After the Spanish lost control and the British took over, they considered Southern Europeans to be "less European" and as a result, they were times when this mixed group (French Creoles) tended to intermarry with Southern Europeans (Portuguese, Corsican and Spanish).