Iberian?

[mwauthy]

I’ve seen this question talked about incompletely many times in several threads; however, I’ve yet to see it clearly answered. Why is there such a huge discrepancy for the “Iberian” or “Southwest European” category amongst the different companies?


On Ancestry, DNA Land, and Wegene I receive anywhere from 20%-25% Iberian, Southwestern European, and Spanish. I have no known ancestors from those areas but I do have significant Northwestern French ancestry. On FTDNA 2.0 I receive 0% Iberian and on 23andMe I receive 0.8% Iberian. This is not a small discrepancy but rather is a huge fundamental difference in understanding of that category. How is it that all these companies can agree about what “Irish” is, yet have such drastic interpretations of this region?


On Ancestry Basque people tend to score 100% Iberian. Hence, I figured this meant that this category was a Basque component. However, I have no known Basque ancestors and on the Eurogenes K36 algorithm I only receive 4% Basque.
I’ve heard other people mention it was a Western Early European Farmer component. If that is true I can accept that. However, what I don’t understand is why 23andMe would group my EEF into the northwestern European category, FTDNA would group my EEF into the West and Central European category, and the other three companies would assign it to Iberian, Southwestern, or Spanish?


I’ve also heard that this occurs because of the lack of French DNA samples. I don’t buy that argument because the lack of DNA samples applies to all of the companies. It doesn’t explain the fundamental difference in interpretation of these specific genes. After reading several threads I’ve noticed this Iberian discrepancy applies to many people and not just myself. Any further insight would be much appreciated.

 

[New Englander]

Ancient Celt Iberian can be found from Ireland to France to Italy.

 

[Pax Augusta]

Ancient Celt Iberian can be found from Ireland to France to Italy.

It's not ancient Celt Iberian, it's Iberian-like neolithic component.

 

[mwauthy]

It's not ancient Celt Iberian, it's Iberian-like neolithic component.

Fair enough; however, that doesn’t explain why 23andMe is tossing that component in the northwest European category, FTDNA in the West and Central European category, and other companies in the Southwestern European category?

 

[Jovialis]

This is what National Geographic describes as Southwestern European:

http://www.eupedia.com/forum/thread...kipedia)/page8?p=518694&viewfull=1#post518694

As a Reference: geno2 Helix
Southwestern Europe:
Interestingly, Southwestern Europe may have been the last refuge of the Neanderthals, due to its relatively sheltered position during the last glacial maximum. European hunter-gatherers also may have taken refuge there 20,000 years ago. Eventually, the first farmers arrived in the region from the eastern Mediterranean, and these are the ancestors of the modern-day inhabitants of the Iberian Peninsula and neighboring regions. Connections across the Mediterranean, dating back to prehistory and down to the medieval period, connect Iberians with other coastal peoples, especially groups in Northern Africa. Some Southwestern Europeans also migrated across the Straits of Gibraltar, leading to a mutual genetic exchange. This cluster was also the pioneer Explorer, the group that expanded over 500 years ago to the Americas, as the Spanish and Portuguese established empires around the world.

There's another component that they call West Mediterranean, which is more associated with Sardinia and Corsica, according to the same national geographic test. Though it does overlap into Southern France, Parts of Italy, and Iberia. I suspect this is the population that get's subsumed into what other companies call Iberian. Which may be why non-Iberians get Iberian as a component. People from Iberia get Southwestern European & West Mediterranean as their predominate autosomal admixture according to the Nat Geo test.

 

[Pax Augusta]

Fair enough; however, that doesn’t explain why 23andMe is tossing that component in the northwest European category, FTDNA in the West and Central European category, and other companies in the Southwestern European category?

Because all these companies follow different criteria.

 

[Jovialis]

@ mwauthy

http://www.eupedia.com/forum/thread...n-in-results-from-different-testing-companies

You should look into reading this thread.

Edit: I see you're already a participant in it.

 

[mwauthy]

Because all these companies follow different criteria.

This is the issue I would like to address and to delve deeper into. I presume all of the companies have the goal of providing an accurate ethnicity estimate. I also presume the companies are using some sort of scientific method in basing their “criteria.”

Assuming these two premises are true why would one company consider these “Iberian or Basque or Neolithic or EEF” genes to be so important as to label 1/4 of my ethnicity estimate as being such, while another company does not see any point in acknowledging or labeling these genes at all and giving 0%.

I believe these genes are there and that neither company is “incorrect.” I just don’t understand the subjectivity and relativity of these “criteria” when creating these regional ethnicity estimates and the labeling that arises with them.

 

[mwauthy]

This is what National Geographic describes as Southwestern European:


There's another component that they call West Mediterranean, which is more associated with Sardinia and Corsica, according to the same national geographic test. Though it does overlap into Southern France, Parts of Italy, and Iberia. I suspect this is the population that get's subsumed into what other companies call Iberian. Which may be why non-Iberians get Iberian as a component. People from Iberia get Southwestern European & West Mediterranean as their predominate autosomal admixture according to the Nat Geo test.

That’s an interesting theory. So some companies just incorporate this Neolithic farmer component into their Western European percentages and treat “Iberian” more like Western Mediterranean.

 

[Gabriel Prola]

Hi, everyone! Maybe someone could help me...
I'm very interested in genealogy and I have been researching my own for more than 10 years. However, I know very few about genetics and stuff. I ordered a DNA test at Family Tree DNA for my grandfather, and now some of the results are intriguing me.
He is an "average" southern Brazilian, with Portuguese blood as well as other European origins like German and French. The German and French known origins were perfectly confirmed in the test, corresponding to his 50% of "West and Central Europe" cluster. However, the other 50%, which I thought were only "Portuguese" (maybe with a trace of "Flemish", as the first settlers of Azores), appeared more diversified in the test: 30% Iberian, 4% North Africa and, surprisingly, 16% from Southern Europe.
I started to make some considerations. I would like to know if I'm right or wrong...
1) First of all, what is the real significance of being an Iberian? If the modern Iberian people (Portuguese and Spanish) are a mixture of Celts, Phoenicians, Germans, Moors and so on, why "Iberians" aren't merely "Southern Europeans" too, like Italy and Greece? In other words, if Iberians are so diverse, why they figure as one of the ethnic clusters of the DNA tests?
2) The 4% of North Africa indicates the Moor presence in the Iberian Peninsula until the 1400's, right? So, if Brazil was colonised from the 1500's, every Portuguese descendant should have more or less the same 4% of Moor blood, right?
3) I have read that this kind of test verifies our origins until about 500 years ago. What does it mean in practice? I mean, if the world history is made of migrations, and we came all from Africa, and I my grandfather doesn't have any African percentage, so the test indicates the region where his ancestors were 500 years ago?
4) Here the most important question: I'm absolutely sure that my grandparent doesn't have any Italian or Greek ancestor for at least the last 300 years. So, the considerably high amount of "Southern European" on his test (16%) could indicate the Ancient Roman presence over the Iberian Peninsula? I've read that modern Iberians have very few of greek and italic origins, so I found it strange...

Thanks a lot!

Gabriel Prola