hispanic genomic diversity, part I: european, african, and amerindian admixtures and the taíno “extinction” controversy

N.B.: This post deals with the variance in European, African, and Amerindian/Taíno admixture in five of the twenty Hispanic subgroups, as well as the Taíno “extinction” controversy.

A few weeks ago, I stumbled upon an interesting article on Hispanic genomic structure and admixture; the paper focused on several Hispanic subgroups – namely, Dominicans, Puerto Ricans, Colombians, Ecuadorians, and Mexicans.

Among this paper’s many findings:

  • Consistent trend of sex-biased admixture (mainly between European men and Amerindian/African women) – not only in the subgroups studied, but in others; the authors cite research showing similar admixtures in Argentina, Cuba, Brazil, Uruguay, and Costa Rica.
  • Differences in (and degree of) European ancestry correlate with risk for some diseases (e.g. asthma in Puerto Ricans – though socioeconomic status moderates this relationship – and breast cancer in Hispanic women); African ancestry correlated with cardiovascular disease and hypertension in some Puerto Ricans.
  • Dominicans and Puerto Ricans have the highest rates of African ancestry among the subgroups studied.

Before I continue, allow me to elaborate on that last point. According to the paper, the Dominican sample had a mean African admixture rate of 41.8% (s=16%) while the Puerto Rican sample had a mean rate of 23.6% (s=12%). The high African admixture rate in Dominicans is likely due to Quisqueya’s post-colonial history; the Atlantic Slave Trade and the Haitian Revolution – along with Haitian control of Quisqueya – likely drove the high African rates there.

Further in the paper, the researchers show that African ancestry in Hispanics is mainly derived from West Africa; specifically, a link between Colombians/Ecuadorians and the Bantu (mainly from Kenya) and Dominicans and Puerto Ricans to the Yoruba (mainly from Nigeria, although some Yoruba also inhabit Ghana, Togo, the Ivory Coast, Brazil, and parts of the U.S. and the U.K.).

(An interesting fact about the Yoruba: they have the highest dizygotic twinning rate in the world – roughly 4.4% of all births!)

In contrast to Dominicans and Puerto Ricans, Ecuadorians and Mexicans have the lowest levels of African admixture (xEcu=7.3%, sEcu=5%; xMex=5.6%, sMex=2%); the latter two groups also have the highest levels of Amerindian admixture (xEcu=38.8%, sEcu=10%; xMex=50.1%, sMex=13%). An analysis in another paper on Hispanic genetic epidemiology shows that Puerto Ricans have roughly 66% European ancestry compared with 45% for Mexicans; for African ancestry, the figures are 16% and 3% respectively and for Amerindian ancestry 18% and 52% respectively. A 2010 article in Dominican Today references a study showing that 15% of Dominicans had Taíno genetic markers (through mtDNA); another 15% had European/Eurasian markers and 70% African markers. While this 70% figure differs significantly from the 41.8% figure referenced earlier, the wide deviation in the latter leads me to believe that it’s not an unusual value.

The differences in European and African ancestry between Dominicans and Puerto Ricans might explain why Puerto Ricans, on average, are lighter than Dominicans. Being part Dominican and part Puerto Rican myself, said differences might also (partly) explain my affinity for Black people (e.g. through active membership in a church with a predominantly Black (Caribbean/West Indian) congregation) and attraction to Black women… 😉

Moving on…speaking of Amerindian admixture, there is some controversy about such admixture in Dominicans and Puerto Ricans – especially the latter group. The controversy involves the so-called “extinction” of the Taíno. Anthropology professor John Hawks blogged about the controversy two years ago; there, he highlighted a 2011 Nature article on the Taíno that initially referred to the ethnicity as “extinct.” As you can guess, this caused outrage among those identifying themselves as Taíno (whether through culture, genes – e.g. mtDNA – or both); Nature removed the “extinct” reference soon after. Here are a few excerpts from Hawks’s post:

“Extinct” just is not a term that should apply to the ancestors of living people. Whatever the dictionary may say, to an ordinary reader or listener, the closest association of “extinct” is probably “dinosaurs”. Extinction without issue. Even when we refer to cultural practices, the term “extinct” invites confusion. Extinction implies a model of disappearance that is sudden and complete, which in many cultural contexts didn’t happen.
Genetic observations themselves have contributed greatly to the revival of the concept of Taíno identity. By demonstrating the high fraction of indigenous ancestry in Caribbean people, genetics has provided something more “real” to people than their cultural ties may seem. Past studies of admixture in the Caribbean were hailed by activists as “scientific proof” that the Taíno still exist. That is one of the anthropological problems: the geneticists are not neutral players in this social milieu, even if they have no commitment to any possible result.

(Emphasis mine.)

Razib Khan also chimed in (here’s an excerpt):

It is undeniable that the Amerindian ancestry found in the Caribbean probably derives from that pre-Columbian population. And it may be that there are cultural forms which exhibit unbroken continuity. But it seems that the modern Taino are a re-precipitation out of a cultural milieu whose Amerindian self-identity had gone extinct.

(Emphasis not mine.)

As you can see, the controversy here is two-fold. First, the reference to the Taíno as an “extinct ethnicity” despite evidence showing that some of today’s Hispanics have Taíno genetic markers. Second, the Taíno “cultural revival” sparked by this evidence (where many self-identify as Taíno even if their genetic admixtures are predominantly non-Taíno – e.g. European or African).

Hawks and Khan aren’t the only ones to discuss the controversy. Jorge Estevez, editor of the Caribbean Amerindian Centrelink page, has a page with a long list of sources and excerpts from same he says demonstrates Taíno cultural and biological survival in the Caribbean (namely, in Cuba, Haiti, Jamaica, Puerto Rico, and the Dominican Republic). (The links in question now lead to merchandise pages and not the sources in question; it seems Estevez lost the domain.) For several years, Jorge Estevez has extensively debated Dr. Gabriel Haslip-Viera, a sociology professor and director of the Program in Latin American and Latino Studies at City College (hey, that’s where I attained my M.Eng.!) over Taíno identification, political motives for same, and whether or not Taíno genetic markers in current Hispanic populations (mainly Puerto Rican) are significant; the debate apparently began when research by Dr. Juan C. Martínez-Cruzado et al. showed that, based on a random sample of 800 Puerto Ricans, over 61% of them possessed Taíno mtDNA. The findings were widely publicized as evidence that the Taíno were not “extinct” (That the Taíno were “extinct” was apparently the consensus before Dr. Martínez-Cruzado’s paper).

In response to this, Dr. Haslip-Viera published a paper in 2006 stating that Dr. Martínez-Cruzado et al.’s findings were insignificant due to larger European and African admixtures; further, he defended the Taíno extinction theory based on a lack of evidence for pure Taíno survivors (i.e. direct descendents as opposed to mixed-race).

Estevez responded in his paper Amerindian mtDNA in Puerto Rico: When Does DNA Matter?; Dr. Haslip-Viera responded with a paper of his own. To make a long story short, Estevez defends Martínez-Cruzado et al.’s findings and maintains that the Taíno aren’t extinct, despite current population being mixed-race; Dr. Haslip-Viera maintains his position that said findings mean little vis-à-vis today’s Puerto Ricans, Dominicans, and Cubans. (N.B.: IIRC, pre-colonial Puerto Rico, Cuba, and Quisqueya had the largest Taíno populations in the Caribbean.)

The debate doesn’t end there. In late 2011, Dr. Haslip-Viera wrote an article called The Myth of Taíno survival in the Spanish-speaking Caribbean; here’s an excerpt:

It also needs to be said that the genetic make-up of Puerto Ricans, Dominicans, and Cubans has little or no connection to the way race and ethnicity are socially constructed at the present time in the Spanish-speaking Caribbean and its Diaspora. The traditionally crude and simplistic Eurocentric concepts of race and ethnicity and their connected patterns of prejudice and discrimination, aimed mostly at persons defined as black or mulatto, continue to prevail among Puerto Ricans, Cubans and Dominicans. This has occurred despite efforts to promote a “rainbow” model of race mixture.

These concepts have also been adopted by the later day Taínos to justify their claims for a pure indigenous pedigree. This is, in part, an attempt to separate them from persons of African background and from Europeans – especially Spaniards – who they see as colonial oppressors whose contributions to society and culture is to be ignored or rejected in the articulation of their identity.

(Emphasis mine.)

Methinks there are some problems with these assertions. Firstly, that race and ethnicity are “socially constructed” is only partly true – race and ethnicity do have a biological/genetic basis; hence, the genetic make-up of Puerto Ricans, Dominicans, and Cubans would, in my estimation, have some connection to the “social” construction. Secondly, Dr. Haslip-Viera’s claim that the so-called “later day Taíno” identify as such to distance themselves from cats with African/European backgrounds is dubious IMHO; a person with Taíno genetic markers is at least part Taíno; why not acknowledge this fact – especially given that some Puerto Ricans and Dominicans have Amerindian ancestry to begin with?

Anyhow, Estevez responded yet again to Dr. Haslip-Viera in the comments section (reproduced here); there was, however, another response to Dr. Haslip-Viera’s article. Written by Roberto “Mukaro” Borrero, President of the United Confederation of Taíno People, the article strongly rebukes Dr. Haslip-Viera for his claims and assertions; Dr. Haslip-Viera’s response was just as strong. Borrero responded to that volley in this article.

In all likelihood, the debate didn’t end there, but I think y’all get the point; Taíno identification and the survival/extinction theories remain controversial today. My view is this: the Taíno aren’t extinct (though there are few – if any – direct descendents), given that distinct Taíno markers live on through today’s tripartite people (i.e. Dominicans, Puerto Ricans, and Cubans – possibly others).

Returning to the paper on genome-wide Hispanic admixture, there’s this finding:

European segments show the lowest FST values when compared with Southwest European populations (individuals from Spain and Portugal), as well as French and Italian individuals. Native American segments of the Hispanic/Latino individuals show the least genetic differentiation with Mesoamerican (e.g., Maya and Nahua), Chibchan (e.g., Colombian), and Andean (e.g., Quechua) populations. The closest relationship is clearly observed between Mexicans from Guadalajara and Nahua indigenous individuals.

Here’s another finding from the same paper about Y chromosome and mtDNA haplotypes:

We found an excess of European Y chromosome haplotypes and a higher proportion of Native American and African mtDNA haplotypes, consistent with previous studies. In addition, we found several non-European Y chromosomal haplotypes with most likely origins from North Africa and the Middle East [I recall a certain chick blogging about this; can’t find the exact posts though…]. We observed that African-derived haplotypes were the predominant origin of mtDNA in Dominicans (17 of 27 individuals), matching the greater African vs. Native American origins of this population on the autosomes and X-chromosomes. However, in Puerto Ricans we did not find evidence of a high African female contribution. The predominant Y chromosomal origins in the Puerto Ricans sampled were European and African; but, in contrast, 20 of 27 Puerto Rican individuals had mitochondrial haplotypes of Native American origin, suggesting a strong female Native American and male European and African sex bias contribution. Overall, in all of the Hispanic/Latino populations that we analyzed, we found evidence of greater European ancestry on the Y chromosome and higher Native American ancestry on the mtDNA and X chromosome consistent with previous findings.

(Emphasis mine.)

While these findings are significant, there are some caveats – namely, small sample sizes and mtDNA’s utility (which, incidentally, was a focal point in the Estevez/Haslip-Viera debate); needless to say, the evidence shows just how diverse Hispanics really are – and this paper focused on just a quarter of the Hispanic subgroups!

Speaking of the Hispanic subgroups, I’ll end this post by returning to the paper on Hispanic genetic epidemiology. Digging further into that paper, one finds:

  • In Puerto Ricans, degree of African/European ancestry (specifically, less of the former and more of the latter) positively correlated with SES.
  • Racial self-identification also correlated with several items, including SES and education.
  • Caveats: because of Hispanics’ tripartite nature (or bipartite for those lacking Amerindian ancestry), racial confounding affects interpretation of the results (and any inferences on causality).

That’s all for now! My next Hispanic HBD post will focus on Puerto Ricans for sure; in the next part of this series, I’ll research some of the other Hispanic subgroups in detail.

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