Aug 03 2011

Do It Yourself Genetics

Category: Brazil,Evolution,genetics,multiculturalismJames @ 5:05 pm

A new industry of direct-to-consumer genetic tests is springing up which let you get information about your ancestry and genetic traits. For Christmas, I ordered a test from 23andme. I’ve discovered interesting information about my health (such as that I am unlikely to get Parkinson’s disease when I get old) and my ancestry.

The ancestry part of it has been particularly fascinating, given my mixed ethnic background (my mom is Brazilian, and Brazil is a real melting pot of races and cultures). The first interesting thing that I discovered is that my mitochondrial DNA is from the L3 haplogroup, which means that four or five hundred years ago, my direct maternal ancestor was probably living in what is now Mozambique, and she was almost certainly brought to Brazil as a slave — it has been interesting to get little bits of information about my ancestors that I never could have known before. The 23andme data also showed that I had some indigenous ancestry as well (listed as “Asian” in 23andme’s results, but Native American DNA shows up as Asian, since Native Americans are descendants of Asians who came across the Bering Strait ).

The Dodecad Project is an online project which collects and analyzes samples of people who have done tests from places like 23andme. They have just released a tool which you can use to analyze your 23andme data to get an idea about the percentages of admixture from 12 different ancestral groups in your own genotype. It is an interesting way to get an idea about where your ancestors came from.

Here are my results from the tool:

East_European                 11.17%
West_European                42.00%
Mediterranean                  28.65%
Neo_African                    1.02%
West_Asian                     7.05%
South_Asian                    0.88%
Northeast_Asian               2.16%
Southeast_Asian               1.71%
East_African                    0.39%
Southwest_Asian              1.92%
Northwest_African           2.78%
Palaeo_African                 0.27%

As you can see, I’m mostly European / Mediterranean, with added admixture of a little bit of everything else. I wonder if the Northwest African / West Asian / Southwest Asian indicate some Moorish ancestry from my Portuguese ancestors who moved to Brazil.

I can’t wait until it is cheap enough for anyone who wants to sequence their entire genome. Until then, all of these tools are very interesting indeed.

3 Responses to “Do It Yourself Genetics”

  1. Rafael says:

    Though the Western European ancestry is the largest, you have a great deal of Eastern European admixture as well. If I had to guess, I’d say your father is of German or Swedish ancestry. Am I right?

    Your Asian is entirely Native American. Dodecad was created to track ancestry among Old Worlders, and doesn’t use Native American DNA as a reference from which to estimate admixture. Thus Native American ancestry is detected under other labels: the Northeast and the Southeast Asian ones. Often, and this is also your case, “Northeast Asian” receives most of the total Native component. This is so because Native Americans descend from Siberians, who make up the Northeast Asian reference population on Dodecad. By contrast, most of the ancestry among those of Japanese or Chinese origin appear under the Southeast Asian label.

    Dodecad shows that ancestry components in Europe correlate with geography. Thus, populations from Northeast Europe – the Fins, the North Russians, and to a far smaller extant, the Swedes – have a degree of Mongolid admixture derived from contact with East Asian-like populations in Northernmost Europe. By contrast, Greeks and Italians, who are geographically close to the Middle East, have a large degree of West and Southwest Asian ancestry. In Iberia, and specially in Portugal, there’s a degree (from 3-7%) of Northwest African ancestry. Again this makes sense if one takes geography into account. When such admixture spilled over to the region, nobody knows. Most connoisseurs believe Europe’s genetic makeup has been defined largely in prehistory: the debate, in fact, is when in prehistory this has happened; the Neolithic, the Paleolithic, the Metal ages? At any event, historical events, such as the Moorsish invasion of South Europe, aren’t thought to have impacted European ancestry to any significant degree.

    • James Rogers says:

      Thanks for your analysis of my data! My dad’s ancestry is mostly English, actually. I figured that the Asian would all be from indigenous populations on my mom’s side — we have no family genealogical information about any Asian ancestors, but we do have at least one story Brazil about a great great grandfather marrying an Indian.

      I’d be curious to know why the Moorish invasion isn’t thought to have left a genetic imprint. The Moors ruled parts of the Iberian peninsula for about 500 years. There seemed to have been plenty of intermarriage during the Moorish rule, and there were lots of conversions to Catholicism during the reconquista, weren’t there? There appear to still have been significant numbers of crypto-Muslims living in Spain several hundred years after the reconquista, and some researchers apparently think that the moors left their genetic signature in the Iberian population. From Wikipedia (https://secure.wikimedia.org/wikipedia/en/wiki/Moors#The_Moors_of_Iberia):

      The Inquisition was aimed mostly at Jews and Muslims who had overtly converted to Christianity but were thought to be practicing their faiths secretly. They were respectively called marranos and moriscos. The Inquisition also attacked heretics who rejected Roman Catholic orthodoxy, including alumbras, who practiced a personal mysticism or spiritualism. The latter represented a significant portion of the peasants in some territories, such as Aragon, Valencia or Andalusia. In the years from 1609 to 1614, the government expelled such subjects. The historian Henri Lapeyre estimated that this affected 300,000 out of an estimated total of 8 million inhabitants.[14]

      Many Muslims converted to Christianity and remained permanently in Iberia. This is indicated by a “high mean proportion of ancestry from North African (10.6%)” that “attests to a high level of religious conversion (whether voluntary or enforced), driven by historical episodes of social and religious intolerance, that ultimately led to the integration of descendants.

      • Rafael says:

        22% of East European ancestry is very high a number of an Englishman. On Dodecad, the British (and the Irish) samples are on average only 2-5% Eastern European. It’s not impossible that you have some Eastern European ancestry that you don’t know about.

        As for the Moorish question – some years ago this paper came out suggesting that a large amount of modern Iberian paternal lineages had a Moorish (10%) or Sephardi Jewish (20%) origin. The argument was that haplogroups prevalent among those populations – J and E – make up 30% of the Iberian Y chromosome pool. The conclusion however has been widely contested on the grounds that the large majority of Iberians with those haplogroups fall in different subclades from those that exist in the Middle East and North Africa (ME/NA) region. In other words, there’s little genetic support for the idea that many Iberians have *recent* ancestry from those regions. It would appear instead that thousands of years ago male migrants from ME/NA, who carried haplogroups J and E, migrated to Iberia. But in the mean time the subclades that evolved in Iberia became distinct from those of ME/NA.

        As for the Moorish-Christian marriages, I think there’s evidence that, by the time of the Moorish expulsion from Iberia, many Muslims were ethnic Europeans. (I have to look further into this, though.)

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