How much Roman Italian DNA do Iberians have?

Luso

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I saw a video titled "Spain, Portugal have Roman Italian ancestry" and in the video the guy believes we have upwards of 30-40% Roman DNA. His theory is based off of the closeness to a north italian cline on g25 plots, and that our roman is from north italia. But I do not agree. This seems to just be an algorithm overfitting because north italians are already close to Portuguese and Spanish in ancient admixture. Instead, I believe our Roman is imperial era (southern-central italian-like) it would explain why our cline jumps from basque-like to more southern and closer to north italian.

Anyone have any idea of how much of this roman admixture we have?
 
I have no idea how that would be computed, although it's true that southern Iberia was home to quite a few colonies for Italic settlers. I am pretty close to some Roman Era Spanish samples, but I assure you someone with my genetic make-up would not turn Basques into people from, say, Extremadura.

Maybe you should also consider how all North African dna got to Iberia.
 
^^Indeed. The genetic make-up of the first colonists would have been close to Republican Romans perhaps, or to Etruscans. With the passage of time, the colonists might have been drawn from areas in Italy heavily settled by Gauls (Livy, of course, was a proud Roman, but his genetic make-up would have been different from someone from Pompeii who also identified as a Roman), and Greek Italy as well.

Then, Roman roads opened up the whole of the Empire to travelers, merchants, even slaves, from all parts of the then known world. Who knows who stayed and who was just passing through.

Of course, we then have the arrival of the Moors and Arabs after the fall of Rome. We have samples of such people buried in Iberia.

The strivings of the Spanish and Portuguese crowns and the Holy Office to expel every last Morisco and Sephardic Jew were mighty indeed, but the uniparentals, if nothing else, tell us some people hid and remained.
 
I have no idea how that would be computed, although it's true that southern Iberia was home to quite a few colonies for Italic settlers. I am pretty close to some Roman Era Spanish samples, but I assure you someone with my genetic make-up would not turn Basques into people from, say, Extremadura.

Maybe you should also consider how all North African dna got to Iberia.
Yes, my family is from the southern tip of Portugal so it's always been assumed we'd turn out with elevated roman, moor, and Phoenician ancestry. Although, actually as most genetic nerds know, southern tip, or northern tip is genetically indistinguishable in iberia.

In terms of North African DNA, we actually have a very plausible theory for how it got into Iberia. Through the Romans! Although, i'm sure the dna has been in the southern areas of the peninsula forever because of the geographic closeness. Anyway, back to the theory. We know from the Iron Age stability paper that north african dna in, particularly, western iberia was consistent with modern north african admixture in us today. The admixture was being involved for thousands of years probably before moorish conquest.


I have another thread on this site I made recently titled: "Western Iberian's North African is 100% from Roman era?"

Of course, we then have the arrival of the Moors and Arabs after the fall of Rome. We have samples of such people buried in Iberia.

The strivings of the Spanish and Portuguese crowns and the Holy Office to expel every last Morisco and Sephardic Jew were mighty indeed, but the uniparentals, if nothing else, tell us some people hid and remained.
Yes, absolutely we have moorish remains found every once in a while. That is expected. But even before moorish times north african samples can be found surely, as North African DNA can be picked up in the iberian genome (at least in the west) since before moorish times.
 
First it must be defined what Roman DNA is, then an answer can be tried.

When I talk about Roman DNA I am referring to the Italian-Roman DNA here. Those who plot as south, central, or north Italians from the Roman era. I understand the Roman Empire was a huge place and that many ethnicities are involved with the term "Roman".
 
Would North African slaves have worked in the mines in the Iberia peninsula?
 
Would North African slaves have worked in the mines in the Iberia peninsula?

It seems like a highly plausible theory. I'll show a picture once I can post images... of the Roman mines concentrated in the western Iberian peninsula
 
It's difficult to pinpoint Roman DNA, basically because of the low frequency of haplogroup R1b-U152. We should assume some female ancestry?

Then there's the possibility of analizing J2, E-V13 and G.
Maybe those stayed in the south, which is plausible with the fact that North central Spain(Castilla y León) was depopulated after the muslim conquest.
 
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Depends on whose map of U-152 you use.

Haplogroup-R1b-S28.gif


U152-S28-poE-CT.png


According to MTA, I have Roman-Iberian ancient matches in Barcelona area in the merchant port, near Valencia in a villa, and in a villa in southern Portugal.

Of course, even if you were limiting your analysis to the Republican area and thus to Italics, you'd have to add other haplogroups. Imperial area you'd have to add othes.

It's been examined by scholars already.
 
The southern Portugal appears there, which is a surprise to me, because is just beside Huelva, a Spanish province which has a lot of U6 and M1.

Valencia doesn't have much U152, which is only partially understandable, because even if it has a famous Arab irrigation system; it was a top city in the Mediterranean.

Catalonia we don't know, because is a surviving refugia after the muslim invasion, but also the Frankish marca Hispanica. So could be Roman or after.
 
The shift in Iberia was more intense during the Moorish period than any other period.
 
The shift in Iberia was more intense during the Moorish period than any other period.

No, the shift in Iberia was more intense in the Roman area. It's clear as day because the North African % in west iberia is pretty much exactly the same in the Roman era as it is today, even before the Moorish period had occurred.
 
No, the shift in Iberia was more intense in the Roman area. It's clear as day because the North African % in west iberia is pretty much exactly the same in the Roman era as it is today, even before the Moorish period had occurred.
https://www.nature.com/articles/s41467-018-08272-w
We find regionally varying fractions of north-west African ancestry (0–11%) in modern-day Iberians, related to an admixture event involving European-like and north-west African-like source populations. We date this event to 860–1120 CE, implying greater genetic impacts in the early half of Muslim rule in Iberia. Together, our results indicate clear genetic impacts of population movements associated with both the Muslim conquest and the subsequent Reconquista.
 
We find regionally varying fractions of north-west African ancestry (0–11%) in modern-day Iberians, related to an admixture event involving European-like and north-west African-like source populations. We date this event to 860–1120 CE, implying greater genetic impacts in the early half of Muslim rule in Iberia. Together, our results indicate clear genetic impacts of population movements associated with both the Muslim conquest and the subsequent Reconquista.

Yes, that's what they dated it to that when the study came out. But we just got a newer study with new samples showing that same North African % is linked to an even earlier time period, in the Roman era.
 
Yes, that's what they dated it to that when the study came out. But we just got a newer study with new samples showing that same North African % is linked to an even earlier time period, in the Roman era.
The shift in PCA occurs during during the Dark Ages. How can you interpret that? And most of those migrations in Roman Empire were driven by slavery.
 
With Vahaduo
d633dc18778018eebde2d4297e606251.jpg

6c65cceffd5a06182dfe9c4019bb64f2.jpg

Me

Target: Duarte_scaled
Distance: 2.4560% / 0.02455963
39.4Iberia_East_IA
21.8GRC_Mycenaean
17.4CZE_IA_La_Tene
11.8England_Roman
9.6MAR_EN


Target: Duarte_scaled
Distance: 2.4560% / 0.02455963
39.4Iberia_East_IA:I3324
21.8GRC_Mycenaean:I9033
17.4CZE_IA_La_Tene:I20522
11.8England_Roman:6DT18
6.4MAR_EN:IAM.5
3.2MAR_EN:IAM.7
 
The shift in PCA occurs during during the Dark Ages. How can you interpret that? And most of those migrations in Roman Empire were driven by slavery.

We have to wait for more samples to really say anything yet. I don't know the PCA you're referring to or what ages of samples are being investigated. But with older Portuguese samples predating the moorish period we'll be able to see...
 
First it must be defined what Roman DNA is, then an answer can be tried.

I would define it as autosomal DNA that can be found in samples from Ancient Rome that is not found in samples from Spain dated to just before Roman colonization in Spain.
 

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