Spain and Portugal are fairly well studied countries for Y-chromosomal lineages. Unfortunately no study so far has tested for the Germanic S21/U106 subclade of R1b, and few papers even distinguish subclades of I (those who did only tested for I2a1a-M26).
I have analysed the raw data from Adams et al. (2008) and attempted to identify by myself the subclades of I as well as R1b-S21 by looking for the DYS390=23 values. About 80% of R1b-S21 has the value 23 at DYS390, which corresponds generally to the Frisian L48 subclade (close to 100% of which have DYS390=23). It's not a perfectly reliable method since DYS390=23 is also found at low frequency among some other R1b subclades - although I have excluded those found among the M153 and SRY2627 subclades.
Consequently it is important to compare the frequencies for haplogroups I1 and I2b1 with those of DYS390=23 so as to get a reasonable idea of the impact of Germanic peoples (Visigoths, Suebi, Vandals, Franks) on the Iberian gene pool.
Here is the data.
Aragon (n=34)
I1 = 2 (6%)
I2b1 = 1 (3%)
R1b3 S21 (DYS390=23) = 5 (14.7%)
Asturias (n=20)
I1 = 1 (5%)
I2b1 = 0 (0%)
R1b3 S21 (DYS390=23) = 2 (10%)
Basque Country (n=116)
I1 = 1 (0.85%)
I2b1 = 0 (0%)
R1b3 S21 (DYS390=23) = 14 (12%)
Catalonia (n=80)
I1 = 0 (0%)
I2b1 = 0 (0%)
R1b3 S21 (DYS390=23) = 5 (6.25%)
Castilla La Mancha (n=63)
I1 = 0 (0%)
I2b1 = 0 (0%)
R1b3 S21 (DYS390=23) = 9 (14.2%)
East Andalusia (n=95)
I1 = 0 (0%)
I2b1 = 1 (1%)
R1b3 S21 (DYS390=23) = 8 (8%)
Extremadura (n=52)
I1 = 3 (6%)
I2b1 = 1 (2%)
R1b3 S21 (DYS390=23) = 4 (8%)
Galicia (n=88)
I1 = 4 (4.5%)
I2b1 = 2 (2.2%)
R1b3 S21 (DYS390=23) = 8 (9%)
Northeast Castille (n=31)
I1 = 0 (0%)
I2b1 = 0 (0%)
R1b3 S21 (DYS390=23) = 3 (9.6%)
North Portugal (n=60)
I1 = 0 (0%)
I2b1 = 1 (1.6%)
R1b3 S21 (DYS390=23) = 5 (8.3%)
Northwest Castille (n=100)
I1 = 0 (0%)
I2b1 = 1 (1%)
R1b3 S21 (DYS390=23) = 8 (8%)
South Portugal (n=78)
I1 = 0 (0%)
I2b1 = 0 (0%)
R1b3 S21 (DYS390=23) = 5 (6.4%)
Valencia (n=73)
I1 = 3 (4.1%)
I2b1 = 1 (1.3%)
R1b3 S21 (DYS390=23) = 7 (9.5%)
West Andalusia (n=73)
I1 = 0 (0%)
I2b1 = 1 (1.3%)
R1b3 S21 (DYS390=23) = 7 (9.6%)
Ibiza (n=54)
I1 = 0 (0%)
I2b1 = 0 (0%)
R1b3 S21 (DYS390=23) = 5 (9.2%)
Majorca (n=62)
I1 = 3 (4.8%)
I2b1 = 0 (0%)
R1b3 S21 (DYS390=23) = 6 (9.6%)
Minorca (n=37)
I1 = 0 (0%)
I2b1 = 0 (0%)
R1b3 S21 (DYS390=23) = 4 (10.8%)
The frequency of R1b with DYS390=23 is surprisingly homogeneous all over Iberia, oscillating around 8% and 10% of the male population. Only South Portugal and Catalonia have less than 8%. Three regions exceed 10%: Aragon (14.7%), Castilla La Mancha (14.2%) and the Basque country (12%).
The Basques, however, have less than 1% of I1 and no I2b1 or R1a at all (this was confirmed by other, larger studies on the Basques), an almost undeniable proof that they have close to no Germanic ancestry, if proof was needed. The Basque DNA Project at FTDNA does not have a single R1b-U106 among members who tested for deep clades, and the U106 Project also lacks any member in or near the Basque country. The high percentage of DYS390=23 can therefore be considered to be due exclusively to the extremely high percentage of R1b (85%) among the Basques. If there is 12% of DYS390=23 among the 85% of Basques R1b and none of it is S21, that would give a ratio of 14% of non-Germanic R1b in Iberia that would misleadingly show up as DYS390=23. If I take an average of 9% of DYS390=23 for Iberia and 65% of R1b, we get about the same ratio of 14%. So it is well possible that very little DYS390=23 in Iberia corresponds to actual R1b-S21. Overall I think it is safe to consider that the percentage of R1b-S21 should always be a bit lower than I1.
My analysis of Germanic Y-DNA in Italy has assessed that the Lombards and Vandals at least, who both originated in southern Sweden, carried around 40% of I1, 30% of R1b, 25% of R1a and 5% of I2b1, not unlike modern Swedes. The Vandals probably didn't have much impact on the Iberian population. It is especially the Suebi who left a clear genetic print around Galicia, Portugal and Extremadura. Based on all the Y-DNA studies on Iberia (and not just Adams et al.) the peak of I1 in Iberia is to be found in Extremadura (3.5%) and Galicia (3%), while I2b peaks in Portugal at 3% (although that could include some Celtic I2b2). The Old Castile, founded by the Visigoths, has precious little I1 or I2b1 - one of the blanks on the map of Iberia along with Andalusia and Murcia.
There have been plenty of discussions on the reasons why the former Suebi kingdom had so much Germanic Y-DNA compared to the former Visigothic kingdom. Of all the Germanic peoples from the migration period the genetic impact of Visigoths is the most elusive. I believe that the reason is that the Goths stayed for many centuries in Eastern Europe and nearly two more centuries in the Balkans before invading Italy and Iberia and could have assimilated a lot of non-Germanic people, notably R1a and I2a1b Slavs and predominantly E1b1b, I2a1b and J2 Balkanic people. It would be pretty complicated at the moment to untangle the Balkanic E1b1b and J2 from all the others (Neolithic, Phoenician, Greek, Roman, Jewish, Arabic) found in Iberia. But it is remarkably easy to check the Eastern European I2a1b (M423). It is all the I2a that is not M26. And I cannot reasonably imagine who could have brought it in any number to Iberia besides the Eastern European populations assimilated by the Goths. The I2a Project at FTDNA has three M423-Dinaric-N and one M423-Isles-B2 from Spain.
It's a pity that no study looks at the subclades of R1a in Iberia, and that no member at the House of Spain DNA Project deemed necessary to test for deep clades. The Phoenicians and Jews could have brought some R1a-Z93 to the Mediterranean coast. Apart from that, all the R1a in Spain should have come with the Germanic migrations. It would be interesting to see how much of it is truly Germanic (L664, Z284) and how much is Slavic. By doing the same for Italy, and combining the figures with the percentage of I2a1b (M423), we could get a fairly accurate imagine of how Slavicised the Goths had become before invading the Roman Empire. It's probably no coincidence that the highest concentrations of R1a in Iberia, aside from the Mediterranean coast, are found in northern Castile, Asturias and Cantabria, the core of the old Visigothic kingdom before the Reconquista. The R1a in Cantabria is accompanied by typically East European mtDNA haplogroups like T1, T3, T5, U2, U3, U4 and U5b.
I have analysed the raw data from Adams et al. (2008) and attempted to identify by myself the subclades of I as well as R1b-S21 by looking for the DYS390=23 values. About 80% of R1b-S21 has the value 23 at DYS390, which corresponds generally to the Frisian L48 subclade (close to 100% of which have DYS390=23). It's not a perfectly reliable method since DYS390=23 is also found at low frequency among some other R1b subclades - although I have excluded those found among the M153 and SRY2627 subclades.
Consequently it is important to compare the frequencies for haplogroups I1 and I2b1 with those of DYS390=23 so as to get a reasonable idea of the impact of Germanic peoples (Visigoths, Suebi, Vandals, Franks) on the Iberian gene pool.
Here is the data.
Aragon (n=34)
I1 = 2 (6%)
I2b1 = 1 (3%)
R1b3 S21 (DYS390=23) = 5 (14.7%)
Asturias (n=20)
I1 = 1 (5%)
I2b1 = 0 (0%)
R1b3 S21 (DYS390=23) = 2 (10%)
Basque Country (n=116)
I1 = 1 (0.85%)
I2b1 = 0 (0%)
R1b3 S21 (DYS390=23) = 14 (12%)
Catalonia (n=80)
I1 = 0 (0%)
I2b1 = 0 (0%)
R1b3 S21 (DYS390=23) = 5 (6.25%)
Castilla La Mancha (n=63)
I1 = 0 (0%)
I2b1 = 0 (0%)
R1b3 S21 (DYS390=23) = 9 (14.2%)
East Andalusia (n=95)
I1 = 0 (0%)
I2b1 = 1 (1%)
R1b3 S21 (DYS390=23) = 8 (8%)
Extremadura (n=52)
I1 = 3 (6%)
I2b1 = 1 (2%)
R1b3 S21 (DYS390=23) = 4 (8%)
Galicia (n=88)
I1 = 4 (4.5%)
I2b1 = 2 (2.2%)
R1b3 S21 (DYS390=23) = 8 (9%)
Northeast Castille (n=31)
I1 = 0 (0%)
I2b1 = 0 (0%)
R1b3 S21 (DYS390=23) = 3 (9.6%)
North Portugal (n=60)
I1 = 0 (0%)
I2b1 = 1 (1.6%)
R1b3 S21 (DYS390=23) = 5 (8.3%)
Northwest Castille (n=100)
I1 = 0 (0%)
I2b1 = 1 (1%)
R1b3 S21 (DYS390=23) = 8 (8%)
South Portugal (n=78)
I1 = 0 (0%)
I2b1 = 0 (0%)
R1b3 S21 (DYS390=23) = 5 (6.4%)
Valencia (n=73)
I1 = 3 (4.1%)
I2b1 = 1 (1.3%)
R1b3 S21 (DYS390=23) = 7 (9.5%)
West Andalusia (n=73)
I1 = 0 (0%)
I2b1 = 1 (1.3%)
R1b3 S21 (DYS390=23) = 7 (9.6%)
Ibiza (n=54)
I1 = 0 (0%)
I2b1 = 0 (0%)
R1b3 S21 (DYS390=23) = 5 (9.2%)
Majorca (n=62)
I1 = 3 (4.8%)
I2b1 = 0 (0%)
R1b3 S21 (DYS390=23) = 6 (9.6%)
Minorca (n=37)
I1 = 0 (0%)
I2b1 = 0 (0%)
R1b3 S21 (DYS390=23) = 4 (10.8%)
The frequency of R1b with DYS390=23 is surprisingly homogeneous all over Iberia, oscillating around 8% and 10% of the male population. Only South Portugal and Catalonia have less than 8%. Three regions exceed 10%: Aragon (14.7%), Castilla La Mancha (14.2%) and the Basque country (12%).
The Basques, however, have less than 1% of I1 and no I2b1 or R1a at all (this was confirmed by other, larger studies on the Basques), an almost undeniable proof that they have close to no Germanic ancestry, if proof was needed. The Basque DNA Project at FTDNA does not have a single R1b-U106 among members who tested for deep clades, and the U106 Project also lacks any member in or near the Basque country. The high percentage of DYS390=23 can therefore be considered to be due exclusively to the extremely high percentage of R1b (85%) among the Basques. If there is 12% of DYS390=23 among the 85% of Basques R1b and none of it is S21, that would give a ratio of 14% of non-Germanic R1b in Iberia that would misleadingly show up as DYS390=23. If I take an average of 9% of DYS390=23 for Iberia and 65% of R1b, we get about the same ratio of 14%. So it is well possible that very little DYS390=23 in Iberia corresponds to actual R1b-S21. Overall I think it is safe to consider that the percentage of R1b-S21 should always be a bit lower than I1.
My analysis of Germanic Y-DNA in Italy has assessed that the Lombards and Vandals at least, who both originated in southern Sweden, carried around 40% of I1, 30% of R1b, 25% of R1a and 5% of I2b1, not unlike modern Swedes. The Vandals probably didn't have much impact on the Iberian population. It is especially the Suebi who left a clear genetic print around Galicia, Portugal and Extremadura. Based on all the Y-DNA studies on Iberia (and not just Adams et al.) the peak of I1 in Iberia is to be found in Extremadura (3.5%) and Galicia (3%), while I2b peaks in Portugal at 3% (although that could include some Celtic I2b2). The Old Castile, founded by the Visigoths, has precious little I1 or I2b1 - one of the blanks on the map of Iberia along with Andalusia and Murcia.
There have been plenty of discussions on the reasons why the former Suebi kingdom had so much Germanic Y-DNA compared to the former Visigothic kingdom. Of all the Germanic peoples from the migration period the genetic impact of Visigoths is the most elusive. I believe that the reason is that the Goths stayed for many centuries in Eastern Europe and nearly two more centuries in the Balkans before invading Italy and Iberia and could have assimilated a lot of non-Germanic people, notably R1a and I2a1b Slavs and predominantly E1b1b, I2a1b and J2 Balkanic people. It would be pretty complicated at the moment to untangle the Balkanic E1b1b and J2 from all the others (Neolithic, Phoenician, Greek, Roman, Jewish, Arabic) found in Iberia. But it is remarkably easy to check the Eastern European I2a1b (M423). It is all the I2a that is not M26. And I cannot reasonably imagine who could have brought it in any number to Iberia besides the Eastern European populations assimilated by the Goths. The I2a Project at FTDNA has three M423-Dinaric-N and one M423-Isles-B2 from Spain.
It's a pity that no study looks at the subclades of R1a in Iberia, and that no member at the House of Spain DNA Project deemed necessary to test for deep clades. The Phoenicians and Jews could have brought some R1a-Z93 to the Mediterranean coast. Apart from that, all the R1a in Spain should have come with the Germanic migrations. It would be interesting to see how much of it is truly Germanic (L664, Z284) and how much is Slavic. By doing the same for Italy, and combining the figures with the percentage of I2a1b (M423), we could get a fairly accurate imagine of how Slavicised the Goths had become before invading the Roman Empire. It's probably no coincidence that the highest concentrations of R1a in Iberia, aside from the Mediterranean coast, are found in northern Castile, Asturias and Cantabria, the core of the old Visigothic kingdom before the Reconquista. The R1a in Cantabria is accompanied by typically East European mtDNA haplogroups like T1, T3, T5, U2, U3, U4 and U5b.