I have started a new topic with posts originally from the thread Lie about mtDNA haplogroup frequencies in Spain.
I think that this topic is interesting enough, though potentially controversial, to deserve its own thread. The main questions developed below are :
- How much African DNA is found in the Iberian population ?
- What is the origin of these African haplogroups (e.g. Maghreban, sub-Saharan) ?
- How does this compare to other parts of Europe ?
- What parts of Iberia have the highest frequencies of African haplogroups ?
- How can we explain their presence historically ?
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African MtDNA haplogroups in Iberia
Luis posted below the regional percentages of hg L in Iberia. The overall continental average is 2.25%. With the islands, it is 2.90%. The highest frequency of L is found in Cordoba (8.30%), and the lowest in central Spain and the Basque country (0.66%).
Acording to Helgason et al. (2001), Iberia has 1.42% of North African haplogroup U6. I couldn't find any data for the other two typical Maghreban lineages, X1 and M1, but it cannot exceed the "other" category (1.99%).
Attention ! MtDNA does not equal autosomal DNA !
Before starting this discussion, I would like to explain why the percentage of haplogroups does not necessarily equal the percentage of admixture from the region of origin of that particular haplogroup. For example, 2% of mtDNA L in Iberia does not mean 2% of African admixture.
Imagine that an Black African woman was brought to Europe 2000 years ago. She has children with a European. All her children belong, like her, to hg L. However she is 100% African, but her children are only 50%. Her children all marry white Europeans. Her sons' children won't have any African mtDNA, but about 25% of African autosomal DNA. Her daughters' children will be mtDNA L, and have 25% of African DNA. After 10 generations (about 300 years), if any of her descendant still carries her mtDNA line, they might not have any African autosomal DNA left, but mtDNA will still be there. Those hg L people might be pure Europeans with an African mitochondrial haplogroup. At most they will have 1% of African DNA.
I am not aware of any direct settlement of Black Africans in Iberia. The amount of Black African Y-DNA is negligible like everywhere in Europe. Therefore, all the haplogroup L found in Iberia must be of Maghreban origin. This means that when L reached Iberia, its carriers already had an admixture of European, Berber and Black African DNA. Although 98% of Maghreban Y-DNA is North African (E-M81), up to 90% of their mtDNA lines are European (minimum 50% in the most Africanised tribes in southern Morocco). In other words, when women carrying hg L entered Iberia, their autosomal DNA was mostly European and Berber (or native North African), with only a small amount of sub-Saharan DNA. If that amount was 10%, then it would be more correct to say that each % of hg L in Iberia only represents 0.1% of sub-Saharan African autosomal DNA. Even so, it is very theoretical and it could be less if L was already diluted when it reached the part of the Maghreb which provided the migrants to Iberia.
Y-DNA Haplogroup E in Iberia
For the sake of comparison, here is one of the most complete and up-to-date table of Y-haplogroup E in Iberia. It has 388 hg E samples out of 3553 samples in total (10.9% of E). Here is an explanation of the breakdown.
- 0.48% of sub-Saharan E (E*, E1a, E1b1a)
- 4.62% of Maghreban E (E-M81)
- 1.72% of E1b1b1a (E-M78) and its subclades (E-V12, E-V13, E-V22). E-M78 and E-V22 are the dominant variants, pointing at a Phoenician origin. V12 and V22 are typically Levantine. There is only 0.59% of the typically Balkanic E-V13.
- 0.74% of E1b1b1c (E-M123) + its subclade E-M34, which is most common from the Levant to the Arabian peninsula. It could be either of Phoenician or Arabic origin. Interestingly it peaks around Galicia and northern Portugal. I am not sure how to explain that. Could it be that the Phoenician had trading posts on the North-West coast, as a relay on their way to Britain ?
- 2.84% of E1b1b (E-M215) and E1b1b1 (E-M35), which are the parents of all North African, Middle Eastern and European subclades of E. It could be either North African or Levantine.
Conclusion
Based on the more detailed "mirror" provided by Y-DNA, it is most likely that mtDNA haplogroup L in Iberia is of mixed North African (Maghreban) and Middle-Eastern (Phoenician, Arabic) origin. Indeed, there is about five times more Y-DNA E than mtDNA L in Iberia, and mtDNA L represents about one third of haplogroups among Berbers. Even without knowing the origin of the Iberian E-M215 and E-M35, if combined to E-M81, the percentage for continental Spain would be 6.8%, roughly three times more than mtDNA L, the same proportion as in the Maghreb. Other Berber mitochondrial lineages being identical to European ones (except U6, M1 and X1), they would be undetectable in the Iberian population.
Furthermore, Women were less likely to travel so far away from home during the Arabic conquest, and even during the Phoenician colonisation, so the bulk of mtDNA L must have come almost exclusively from the nearby Maghreb.
I think that this topic is interesting enough, though potentially controversial, to deserve its own thread. The main questions developed below are :
- How much African DNA is found in the Iberian population ?
- What is the origin of these African haplogroups (e.g. Maghreban, sub-Saharan) ?
- How does this compare to other parts of Europe ?
- What parts of Iberia have the highest frequencies of African haplogroups ?
- How can we explain their presence historically ?
----------------
African MtDNA haplogroups in Iberia
Luis posted below the regional percentages of hg L in Iberia. The overall continental average is 2.25%. With the islands, it is 2.90%. The highest frequency of L is found in Cordoba (8.30%), and the lowest in central Spain and the Basque country (0.66%).
Acording to Helgason et al. (2001), Iberia has 1.42% of North African haplogroup U6. I couldn't find any data for the other two typical Maghreban lineages, X1 and M1, but it cannot exceed the "other" category (1.99%).
Attention ! MtDNA does not equal autosomal DNA !
Before starting this discussion, I would like to explain why the percentage of haplogroups does not necessarily equal the percentage of admixture from the region of origin of that particular haplogroup. For example, 2% of mtDNA L in Iberia does not mean 2% of African admixture.
Imagine that an Black African woman was brought to Europe 2000 years ago. She has children with a European. All her children belong, like her, to hg L. However she is 100% African, but her children are only 50%. Her children all marry white Europeans. Her sons' children won't have any African mtDNA, but about 25% of African autosomal DNA. Her daughters' children will be mtDNA L, and have 25% of African DNA. After 10 generations (about 300 years), if any of her descendant still carries her mtDNA line, they might not have any African autosomal DNA left, but mtDNA will still be there. Those hg L people might be pure Europeans with an African mitochondrial haplogroup. At most they will have 1% of African DNA.
I am not aware of any direct settlement of Black Africans in Iberia. The amount of Black African Y-DNA is negligible like everywhere in Europe. Therefore, all the haplogroup L found in Iberia must be of Maghreban origin. This means that when L reached Iberia, its carriers already had an admixture of European, Berber and Black African DNA. Although 98% of Maghreban Y-DNA is North African (E-M81), up to 90% of their mtDNA lines are European (minimum 50% in the most Africanised tribes in southern Morocco). In other words, when women carrying hg L entered Iberia, their autosomal DNA was mostly European and Berber (or native North African), with only a small amount of sub-Saharan DNA. If that amount was 10%, then it would be more correct to say that each % of hg L in Iberia only represents 0.1% of sub-Saharan African autosomal DNA. Even so, it is very theoretical and it could be less if L was already diluted when it reached the part of the Maghreb which provided the migrants to Iberia.
Y-DNA Haplogroup E in Iberia
For the sake of comparison, here is one of the most complete and up-to-date table of Y-haplogroup E in Iberia. It has 388 hg E samples out of 3553 samples in total (10.9% of E). Here is an explanation of the breakdown.
- 0.48% of sub-Saharan E (E*, E1a, E1b1a)
- 4.62% of Maghreban E (E-M81)
- 1.72% of E1b1b1a (E-M78) and its subclades (E-V12, E-V13, E-V22). E-M78 and E-V22 are the dominant variants, pointing at a Phoenician origin. V12 and V22 are typically Levantine. There is only 0.59% of the typically Balkanic E-V13.
- 0.74% of E1b1b1c (E-M123) + its subclade E-M34, which is most common from the Levant to the Arabian peninsula. It could be either of Phoenician or Arabic origin. Interestingly it peaks around Galicia and northern Portugal. I am not sure how to explain that. Could it be that the Phoenician had trading posts on the North-West coast, as a relay on their way to Britain ?
- 2.84% of E1b1b (E-M215) and E1b1b1 (E-M35), which are the parents of all North African, Middle Eastern and European subclades of E. It could be either North African or Levantine.
Conclusion
Based on the more detailed "mirror" provided by Y-DNA, it is most likely that mtDNA haplogroup L in Iberia is of mixed North African (Maghreban) and Middle-Eastern (Phoenician, Arabic) origin. Indeed, there is about five times more Y-DNA E than mtDNA L in Iberia, and mtDNA L represents about one third of haplogroups among Berbers. Even without knowing the origin of the Iberian E-M215 and E-M35, if combined to E-M81, the percentage for continental Spain would be 6.8%, roughly three times more than mtDNA L, the same proportion as in the Maghreb. Other Berber mitochondrial lineages being identical to European ones (except U6, M1 and X1), they would be undetectable in the Iberian population.
Furthermore, Women were less likely to travel so far away from home during the Arabic conquest, and even during the Phoenician colonisation, so the bulk of mtDNA L must have come almost exclusively from the nearby Maghreb.
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