has another article up about admixture in Argentina. The interesting aspect is that in its self-conception Argentina, like the United States of America or Australia, is a European settler nation, and therefore unlike Mexico, Boliva, or Brazil, each of whom de jure or de facto espouse a multicultural and multiracial identity. Buenos Ares is in its mentality more a Southern European city situated in the antipodes, with a touch of old Mitteleuropa (Argentines are avid consumers of psychoanalysis). As noted in the PLoS article, ~1 percent of the citizens of Argentina identify as indigenous, but ~20 percent of the ancestry of Argentina's population seems to derive from Amerindian sources! The paper itself adds little new here. Rather, it increases the sample size, and confirms that the Amerindian ancestry does seem to be lower in Buenos Ares, the magnet for so much Italian immigration. But what is most interesting, though not necessarily surprising, is that of those Argentines who claim four European grandparents (N = 22), the average proportion of European ancestry was 91 percent. The issue here is that an individual who claims four European grandparents should have close to 100 percent European ancestry. So what's going on? First, I think the use of ancestrally informative markers is probably introducing noise; we can't be sure that there won't be residual "non-European" ancestry even in Europeans. Second, the respondents might be honest about what they know, but their grandparents may have not told them the whole truth about their backgrounds With a standard deviation of 9 percent I'm pretty sure that some of these 22 individuals do have substantial non-European ancestry. I don't think ancestrally informative markers would be off that far. For me the key fact to observe is that if you drew 22 random white (non-Hispanic) Americans you are almost certainly to get no more than a few percent non-European ancestry at most. If you selected Americans who claimed 4 European born grandparents there would be almost no non-European ancestry. Over the past year and a half I have done deeper analyses of friends who have received genotypes from 23andMe. These results align with what I've observed. White Americans generally look in vain for Native American ancestry. In contrast, white Latin Americans tend to have substantial non-European ancestry. And intriguingly it seems that many have unknown African ancestry. This highlights the difference between the settlement of Anglo-America, and Latin America. The demographic replacement of Amerindians in Anglo-America was radical and extreme. In contrast, even in self-consciously European settler regions such as South American's southern cone a substantial proportion of Amerindian ancestry is present in contemporary populations. Because of the large number of Native Americans of mixed heritage it is likely that total Native American identified population is actually very similar to the amount of non-Hispanic Native American ancestry in the USA (i.e., numerous non-Native American identified whites and blacks with small quanta of ancestry will sum to be about the same absolute amount as the small number of Native Americans who are substantially indigenous). While 1.5 percent of Argentines identify as indigenous, 1 percent of Americans are Native American.
Finally, on a minor note, many Argentines have African ancestry. The historical reason for this is not too surprising. People of African ancestry were substantial auxiliaries serving the Spanish Empire right up to independence. After independence they were rapidly assimilated in most of the new nations. Despite the fact that a substantial majority of Mexicans have African ancestry, this heritage is unknown to them. Additionally, I'm willing to put down good money that the majority of white Cubans whose own parents did not immigrate directly from Europe also have clearly detectable African ancestry on the genomic level. That would mean that Senator Marco Rubio of Florida is likely a double minority by the rubric of hypodescent, which Americans as illustrious as Halle Berry and Barack Hussein Obama espouse to this day. In fact, the majority of "white Hispanics" are also black according to hypodescent.
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