African DNA

Submitted by admin on Wed, 09/04/2019 - 10:14

En Quora pódese ler  e comprobar de que os mitos de que temos máis "africanos" que ningún en España son, cando menos, moi dubidosos. Ninguén  cita ese dato nesta longa parolada.

Since Portugal and Spain were controlled by the Moors for 700 years, why don't Portuguese and Spaniards have more African DNA?

Ygor Coelho

Ygor Coelho, Native speaker and admirer of Brazilian Portuguese language

Updated Aug 9

Though many Portuguese and Spaniards do show some minor percentage of North African-related ancestry, with the caveat that some of that may have come to Iberia before the Moorish conquests, that may have happened because of many cumulative reasons:

  1. Roughly after the Bronze Age, and especially in the medieval era, when most civilized places of the Old World became already very densely populated, it was much harder for invaders, after a military conquest, and even a large number of immigrants to leave a very big genetic impact in the lands they came to rule. The populations were already large, and in most cases, in the Middle Ages and afterwards, armies moved in and out, conquerors ruled and were expelled, but the bulk of the population was comprised of locals. In most situations of foreign conquest in the Late Antiquity and Middle Ages, the lives of the common people continued pretty much unchanged. The top layer of rulers and leading warriors changed, not much else.
  2. Most Moors were North African Berbers and Arabized Arabo-Berbers, so their genetic impact isn’t immediately visible even among those who may harbor a much higher than average percentage of medieval Moor-derived ancestry.
  3. It is likely that the proportion of Moor-related ancestry was higher among those “recalcitrant” Muslims and Jews who lived near the Mediterranean coastal areas and were partially expelled from Spain in the early modern era.
  4. Moors were mostly a military and ruling class that concentrated, much more than the indigenous Mozarabic peasants, in the cosmopolitan big cities of Al-Andalus, and as we know most cities of the past may have glittered with luxuries and splendor, but the sad fact was that, without the revolution of modern science and public health policies, they were in general extremely dense and unhealthy places that acted as “demographic sinks”, with a much lower long-term population growth than the little villages and farms away from the large towns. Thus, if a pre-modern population was especially concentrated in cities, and not in the fields and pastures, it is quite likely that its genetic impact centuries later became much lower than we’d expect inititally.
  5. Despite some accounts of significant immigration of Berber and Arab families to Al-Andalus, the truth is that, in a nationwide perspective, the number of immigrants from North Africa and the Middle East after the fall of the Visigoths in 711 AD was probably small in comparison with the sizeable Iberian population and area. Most of those who came were somehow related to the military, political and administrative needs of the caliphate. It was not a real and massive folk migration as that which happened in medieval Anatolia and turned it into Turkey, and even there the genetic impact left by the immigrants and conquerors was most probably significant, but minor (estimates generally vary between roughly 1/6 and 1/3).
  6. The Reconquista was a centuries-long affair and gradually squeezed the land, power and prestige of Al-Andalus in the Muslim world. The society of Muslim-ruled Iberia was deeply divided along ethnic/ancestral lines, and there was frequent strife even between Arabs and Berbers, let alone those involving the local Latin-speaking populace. Those people maintained their separate ethnic identity even after centuries, so they probably did not mix with each other as much as some would think.
  7. Since the descendants of the Moors were apparently much more connected to the political status quo and the ruling classes, I’m pretty sure they would’ve also been significantly more affected by the gradual but continuous takeover of those territories by the Northern Christians and the subsequent political changes. That meant not just a higher risk to die fighting for their established social status, but also a higher likelihood of fleeing and eventually emigrating back to the Maghreb.
  8. After the Christians reconquered former Muslim-ruled territories, they usually brought in a numerous number of new settlers from the Northern Iberian kingdoms to occupy the land and ease the political, cultural and religious transition of their new territories away from the former Arabized and Islamized status quo (even if a large part of the population remained Christian in many parts of Al-Andalus). Those northern settlers, who had escaped the Arabo-Berber conquest, probably diluted the Moorish-related ancestry in the local populations that were previously subject to Muslim rule.

 

James Souttar

James Souttar

Jun 2, 2018 · 2 upvotes including Ygor Coelho

In the entry on ‘genetic history of the Iberian Peninsula’ Wikipedia records:

“Recent Mitochondrial DNA studies coincide in that the Iberian Peninsula holds higher levels of typically North African Haplotype U6, as well as higher frequencies of Sub-Saharan African Haplogroup L in Portugal. However, high frequencies are largely concentrated in the west and south of the Iberian peninsula and therefore overall frequency is higher in Portugal (6.83%) than in Spain (1.9%) with a mean frequency for the entire peninsula of 3.83%. There is considerable geographic divergence across the peninsula with high frequencies observed for South West Castile (8%), Southern Portugal (18.80%), Central Portugal (10.70%), Western Andalusia (14.6%) and Córdoba (8.30%).

“Current debates revolve around whether U6 presence is due to Islamic expansion into the Iberian peninsula or prior population movements and whether Haplogroup L is linked to the slave trade or prior population movements linked to Islamic expansion. A majority of Haplogroup L lineages in Iberia being North African in origin points to the latter.”

(more)

Ygor Coelho

Ygor Coelho

Original Author · Jun 4, 2018 · 1 upvote

Interesting data, thanks for this informative comment. That said, I’d be very wary of assigning two milennia-old mytochondrial haplogroups, especially in their basal, most ancient form (not its derived, downstream subclades, which are much more recent and specific), necessarily to a North African “Moorish” immigration.

Haplogroup U6, for instance, is estimated to date back to some 30,000–35,000 years ago. It’s still premature to associate most of its presence in Iberia to the rule of Moors. Haplogroup U6, for instance, is regularly found (in higher than average proportions) in Galicia and even in Southwestern France, two places that most certainly weren’t very directly affected by Arab/Berber settlement and dominion in the Al-Andalus period. Typically African haplogroup L is also found in higher than average proportion in Galicia (Meta-Analysis of Mitochondrial DNA Variation in the Iberian Peninsula), again one of the only regions of Iberia that was not directly subject to Moorish rule for any long time.

Some of it may actually derive from that historic period, but I think it’s really unlikey that most or all of it can be attributed to that period. Even putting that caveat aside for a moment, the percentages are in most cases very minor, with an average of just 3.83%.

It’d be nice if we had much more specific information about the distribution of those haplogroups classified by their specific subclades and their estimated age. By the time the Moors arrived, it’s possible that many of those Mt-DNA haplogroups had been in Iberia for milennia, and the autosomal makeup associated with them could’ve been very different from that found in North Africa.

I doubt that genetic connections and genetic exchanges between North African and Iberian populations started only in the Middle Ages with the Muslim rule, especially if you consider archaeological evidences like the Phoenician and Punic presence in the Spaniard coast, the Bell Beaker Culture expansion to the Maghrebi coast in the Bronze Age, and the genetic evidences of some relations between the Neolithic populations of Maghreb and those of the Iberian Peninsula. There were many historic periods where these small percentages of North African maternal lineages may have arrived in Spain and Portugal, especially if you consider that some of those actually extend to other parts of Western Europe that were never under Muslim/Moorish rule.

 

 

James Souttar: Agreed. However there are two factors which suggest that the Moors may have had a particular impa...

 

Aaron Marquees

Aaron Marquees

Aug 23 · 1 upvote

Wikipedia is not a reliable source and I doubt those are correct…