Wednesday 30 September 2009

Venezuelan colours II

Venezuela is very mixed, as we have often mentioned, but: how mixed is it precisely? What differences are there exactly across social groups?

Population geneticists help to investigate how homo sapiens expanded from Africa to settle the whole world and how different groups intermingled. One of the main sources they have are non-recombining pieces of DNA. These are genetic markers we all get from one side of our ancestors only. Most of the DNA information in our cells are a "random" mixture of both parents' genes: it is not possible to know but some parts get transmitted almost unchanged from father to sons across many generations or from mother to daughters and sons. They are patterns that are recognizable after thousands of years. Only from time to time there are minor mutations and those mutations help us see how different branches of mankind appeared.

The markers on the males' side are patterns of DNA-bases found in the Y chromosomes. I have the same sequences as my dad but for very minor variations. The markers on the female sie are DNA bases found in our mitochondria, little structures we all have in all our cells and which we get exclusively from our mothers. We all have the spitting image of our mother's mitochondria.
As populations in previous times stayed put in some places and did not mingle randomly with others, geneticists have been able to find haplogroups that are shared by all common ancestors of an individual many years ago. Things get much more complicated than that, but basically, with those haplogroups we can track down a whole line, either on the paternal side or on the maternal side of each man and on the maternal side of every woman on Earth.





Like your mother










The Y: like dad's







Sub-Saharan Africans, Europeans, Asians and native Americans have particular haplogroups. If you see a "sub-Saharan" male haplogroup in an European, this means that the father of the father of the father...of that European (a male as only males have Y chromosomes, unless we are talking about very unusual cases) came from sub-Saharan Africa in recent history. The same goes on the female side.

I am Venezuelan and as I wrote in previous posts, I have the usual admixture. My paternal haplogroup appeared in the Fertile crescent around 18000 years ago and it is present in lots of Lebanese, Iraqis, Syrians, Turks, Armenians, Greeks, Southern Italians, Jews and to a lesser extent Spaniards. I got it from there. My mother's haplogroup is sub-Saharan and most likely a female ancestor of mine was a slave brought to Venezuela between 1528 and 1810 (it could have come indirectly through Spain as 1-3% of Spaniards also have sub-Saharan female haplogroups, but that is less likely). That lady was from West Africa. That is only part of my background. As my family has been in Venezuela for a long time, it is almost certain there is native American blood there as well and from other parts of Europe (two of them I know) and Africa. One has 2 parents, 4 grandparents, 8 great-grandparents and 2 times n ancestors n generations ago.

Now back to the study carried out by Rodríguez-Larrade. The blood samples were from 50 and 60 individuals who were in a public and a private maternity respectively.

The results for male haplogroup origin in the public maternity (where the dad of the dad of the dad of the dad...of the males came from) showed this:














The results for male haplogroup in the private maternity showed this:













A lot of the people in public hospitals are people from families who came from the countryside to the capital in the last 50 years. About 40% of the grandparents of the people in the private clinic were born in Europe. As the study says, "Many of these migrants, mostly Spaniards, Italians, and Portuguese, helped to develop economic activities related to commerce and construction, activities that rapidly introduced them to the high socioeconomic level. On the other hand, most of those individuals at the low socioeconomic level are a consequence of rural-urban internal migration; they seem to be more representative of the traditional Venezuelan population. This reveals that the identification of the grandparents' geographic origin is an important methodological aspect to take into account in genetic studies related to the reconstruction of historical events."

Still, in both cases we see the European component on the male side is the dominant by far. Male Indians were killed or outbred in previous centuries, whereas the conqueror or richer settler reproduced more, as all around the world.

On the background we got from our mothers, we have a completely different picture. The background in the public maternity looked like this:














The genetic background on the female side in the private clinic looked like t his:














Let's hope in the future there won't be such differences and our public hospitals become as good as those in Northern Europe. Let's hope any background differences between public and private clinics disappear.

In any case, we sum up saying Venezuelans are, genetically speaking, mostly European on the paternal side and mostly native American on the maternal side, with a sub-Saharan component on both sides (as my maternal haplogroup shows) but any mixture is part of Venezuela and most Venezuelans have a bit of recent background from every continent. There are obvious ethnic differences, although smaller than elsewhere: the poor of the present tend to be descendants of the poor of yore, who tended to be more descendants of Indians and slaves, although it is a matter of some degrees. There has been a lot of mobility in Venezuela for many decades now, probably more than in many other places, although not as we would want. The main reason is the little support given to the quality of education of the poorest, something that hasn't changed.

The cool thing is that a Venezuelan of German or Lebanese, Japanese or Peruvian parents is just that: a Venezuelan with foreign parents, but a Venezuelan 100%. She is also going to eat her arepas and cachapas, she will have the same Venezuelan music, use the Latin American Spanish adorned with those Indian, African and Italian words

Genetics can take us further and teach us more about the history of Venezuela. We will write about this in future posts. But it does not take genetics for us to know we need better education for the poor. This will help us reduce all kinds of social differences and get us on the road to sustainable development.

9 comments:

  1. Hi there, Kepler.

    I'd like to add that, from memory, there was a study on Colombians (could be Venezuelans but rings more like Colombians from the Santa Marta or maybe Cartagena area - it's just a memory) that showed that, while mtDNA was almost universally native, the X-DNA was largely European. This implied that a lot of successive generations of immigrant men had been mating with local women, who preserved the native mtDNA but were each generation more European overall.

    Of course this may not be the case in other regions (and I'd add that in most cases in the Old World the mtDNA rather seems to represent best the overall genetic heritage, rather than the more elusive Y-DNA) but it's a curious phenomenon in an area that was surely the welcome port of many generations of male immigrants but that seldom saw an immigrant woman.

    In other Latin American cases, again from memory (a more recent paper anyhow), the X-DNA was more in agreement with the overall autosomal inheritance. But there were curious variations depending on the population.

    Sorry I can't provide the links but I've lost a lot of bookmarks in computer crashes. I think the latter was a PLoS paper anyhow.

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  2. Hi, Maju.
    Thanks for the references. I will probably find it with the right key words.

    That phenomenon is probably widespread where European males kept arriving in meaningful numbers, as Colombia, Venezuela and probably Argentina and Uruguay, as opposed to Bolivia or Peru.

    As I mentioned earlier, my maternal line is rather European or native-American-European and yet the mtDNA is sub-Saharan. My maternal grandfather looked very Germanic and a great-great-grandfather was from the canary Islands. Probably it happened over and over.

    Still, even in the public hospital there is a small group of European mtDNA in Venezuela.

    That is more so in the cities than in the villages, as you will see from the article I mentioned in your blog.

    You can see my previous post on this
    here, where they talked about autosomal material.

    I forgot to add the percentages in this post, I will update that later some time in the week.

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  3. I think we have already discussed this but just in case: "Sub-Saharan" mtDNA could well be from the Canary islands, and, if so it could be original from the slave trade or genuinely native from the archipelago, as it is precisely the Guanche aDNA which has somehow proven that some L(xM,N) existed in North Africa prior to the slave trade - something I already suspected but was confirmed recently.

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  4. Yeah, I have seen this, there ar also sub-Saharan mtDNA samples in the Iberian peninsula proper, but I think most people with sub-Saharan haplogroups in Venezuela have ancestors from a more direct slave trade, the sub-Saharan mtDNA is definitely higher in Venezuela.

    I have thought about
    this event, where a British pirate, Hawkins brought two ships full of slaves from Guinea to a port not so far from the city where my grandmother and I were born. That was in the XVI century already. There were probably other ships arriving there with more slaves.

    Do you have access to the whole article? My maternal haplotype is not so common.

    ReplyDelete
  5. Do you have access to the whole article? My maternal haplotype is not so common.

    No, sorry. :(

    ...but I think most people with sub-Saharan haplogroups in Venezuela have ancestors from a more direct slave trade, the sub-Saharan mtDNA is definitely higher in Venezuela.

    Sure. I was just mentioning the possibility. L(xM,N) in Spain similarly could be from Canarian native, North African or truly Trans-Saharan origin (there was also many slaves for a time in Andalusia, though most of them were sent to Cuba upon metropolitan abolition).

    I have thought about this event, where a British pirate, Hawkins brought two ships full of slaves from Guinea to a port not so far from the city where my grandmother and I were born. That was in the XVI century already. There were probably other ships arriving there with more slaves.

    It's a logical possibility but you never know. One thing is for sure: our ancestry is always lost at some point in the dark depths of time. Even the most accurate genealogy can only reach that far. I can trace some of my ancestors to Renaissance Italy (more or less arguably) but for the most part only vague references, if any at all, exist for beyond the third or fourth generation back. Maybe it's better that way.

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  6. Yeah, I know, but to some extend in the case of Venezuela the haplogroups tell us a lot of the hardly recorded history we had.

    What? Your ancestors were in Italy in the Renaissance? I thought they had been in Euskal Herria since Magdalenian times behintzat! :-)

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  7. I have a complex ancestry: only like 60% is genuinely Basque. My ancestry also includes an aristocratic Italian line, vassals of the Este family.

    This guy seems to be in my line of ancestry somewhere and this woman too. Though Ponziani was my (maternal) Grandfather's third or fourth surname, these people are anyhow claimed as direct ancestors in my family. A more direct ancestor created the public bank of Modena some 150 or 200 years ago.

    But these are all by my mother's side (her paternal side). But my mtDNA and Y-DNA should both be local, at least as far as I can tell.

    By my Basque strictly paternal side there's a legend of some guy being a privateer, maybe in the Jenkin's Ear War. A safer more recent reference mentions that my grandfather's granfather (or something like that) owned a forge and was owed payement for some horses in the First Carlist War. Whatever the case, my great-grandfather migrated to the city and eventually sold off the family farmhouse to provide for his unmarried sister, both of whom I knew in person when I was very very young.

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  8. Hi Kepler,
    I'm Venezuelan too, followed the Genographic Project route, and later uploaded my results to Family Tree DNA, where I manage a Y dna project for my surname. I became so into it, that even became a member of the International Society for Genetic Genealogy.
    I was absolutely shocked to find out that I'm haplogroup B*.
    Furthermore, B is rare even in Africa, not to mention Venezuela.
    Currently, my DNA is being analyzed by the lab at FTDNA (the company that tests for the Genographic Project) because there are so few of us. They have very few templates for my haplogroup, and as the labs director told me, what they lear about my DNA will benefit future members of HG B--which is no consolation for me anyway.
    I will follow with a mtDNA test--if I ever receive my YDNA refine tests from FTDNA back. They are taking their time.
    I'm glad to discover that I'm not the only Venezuelan interested in genetic genealogy.

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  9. Wao! Y haplogroup B* in Venezuela? That's very unique. There are like 6% of Venezuelans with Y chromosome haplogroups from sub-Saharan Africa, but they are mostly from other types. Whereabouts in Venezuela are you from? I am from Valencia. When did they do the test? It can take time. The initial tests took for me about one month. I have found out much more about my paternal haplogroup and heritage now, I still lack more information from my mother's side, unfortunately. On a recent account I managed to get more information on what part of Spain my paternal ancestor very probably came from and I combined that information with census and voting registries and got some interesting stuff I will be writing about later on. Keep us posted about your results! on Venezuelan colours II

    ReplyDelete

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