R.Rocca
07-24-2013, 12:35 AM
Link: http://www.r1b.org/?page_id=242
A new study by Boattini et al. (2013) has made evident the high frequency of U152 in northern and central Italy (table 1).[1] This distribution has also been observed in prior studies.[2][3][4] For the first time however, we get a clearer picture of the U152′s intra-Italy regional frequency, and we can begin to infer some links to archaeological cultures.
http://r1b.org/wp-content/uploads/2013/06/U152_Only_Map.png
Table 1 – U152 frequency (Boattini et al. 2013)
There is a clear north-south gradient for U152 frequency, but it is slight from the Alps to central Italy and the drop-off accelerates in southern Italy. The tested areas with the highest U152 frequencies are Brescia (51.3%) and Cuneo (40%) in northern Italy, followed by Pistoia (38.5%) in Tuscany. Undifferentiated U152(xL2) has a frequency peak in Brescia and Pistoia (38.5%). If small commercial testing is any indication, Brescia’s U152(xL2) is made up largely of Z36 and to a lesser extent, Z56.[5] In Tuscany, Z36 shares its importance with Z56.[6] STR values of DYS385b ≥16 in U152* samples from LaSpezia/Massa (3 of 3) and Pistoia (2 of 5) might indicate high levels of Z56 subclade Z144/Z145/Z146.
L2(xL20) has its highest frequency in La Spezia/Massa (25.0%) and Treviso (24.2%) and L20 has its highest frequency in L’Aquila (3.3%), although if we look at the small pockets of L20 overall, it looks to be somewhat more common in the north than in the south. L2 as a percentage of overall U152 frequency reaches 39.2% on the Italian Peninsula, 25% in Sardinia and 20% in Sicily. This is in contrast to L2 outside of Italy (table 2). In Italy, L2 only makes up a majority of U152 lineages in the north-east region, and is highest in Treviso overall (80.0%). Unfortunately, subclades Z49 and Z367 were not tested in Boatinni’s L2(xL20) samples.
http://r1b.org/imgs/L2_Percentage_Table.png
Boattini et al. also ran Spatial Principal Component Analyses (sPCA) based on frequencies of Y-chromosome haplogroups. They found a three-partitioned structure of Italian population: 1) North-Western Italy (including most of the Padana plain and Tuscany.), 2) South-Eastern Italy and the whole Adriatic coast, and 3) Sardinia. Lineages contributing more to the differentiation along the first sPCA were R-U152*, and to a lesser extent, R-L2* and R-P312* in North-Western Italy, and G-P15 in South-Eastern Italy (Figure 1a), and I1-M26 in Sardinia (Figure 1b).
http://r1b.org/wp-content/uploads/2013/06/Boattini_sPCA.png
Figure 1. Spatial Principal Component Analysis (sPCA) based on frequencies of Y-chromosome haplogroups.
Copper Age Populations of Northern and Central Europe:
The results of Boattini’s age estimates suggest that most of the Y-chromosomal diversity present in modern day Italians was originated from few common ancestors living during late Neolithic times and the Early Metal Ages. Interestingly, the observed paternal population clusters are similar to dental (Figure 2) and cranial (Figure 3) morphological clusters of Italian Copper Age populations.[11][12] These show a close affinities between the Copper Age people of Northern and Center-West Italy. They also show a relationship between Southern Italian groups. While the Sardinian Copper Age groups are more similar to that of Southern Italy, they are still outliers when compared to all peninsular groups. If haplogroup U152 was already the differentiating Y-DNA group in Copper Age Northern and Central Italy, ancient Y-DNA studies should focus on finding it in the Remedello Culture (Brescia), the Spilamberto Group (Emilia-Romagna) and the Rinaldone Culture (Tuscany and northern Latium). Of particular interest is the Remedello Culture, which groups closely with Bell Beakers in cranial studies.[13]
http://r1b.org/wp-content/uploads/2013/06/Copper_Age_Dental_Traits_v002.png
Figure 2 – Dental traits of Copper Age Italian Populations
http://r1b.org/wp-content/uploads/2013/06/Copper_Age_Skulls_by_Region.png
Figure 3 – Cranial groupings of Italian Copper Age skulls
Ancient Y-DNA from Bell Beaker remains have been found to be R1b.[14] However, it is difficult to see Bell Beakers as a starting point for R1b in Italy, as there is substantial cultural and geographical continuity with the preceding Copper Age groups of Northern and Central Italy.[15] Given that, it is likely that a U152 presence in Italian Bell Beaker groups was the result of continuity from their immediate Copper Age predecessors. The influence of the Central European Bell Beaker Begleitkeramik group does seem to have made an impact in the formative phase of the Polada Culture in northern Italy and the late Bell Beaker period in Tuscany.[16][17] The changes brought on by the Polada Culture are so apparent that, by unanimous opinion, a movement of human groups has been presumed between Central Europe and the Po Valley.[18][19][20] The direction or origin of the gene flow is difficult to assess however. This Early Bronze Age phenomenon may explain why L2 as a percentage of U152 is highest in north-east Italy and makes up a larger amount of U152 outside of Italy.
While mtDNA haplogroup H in Europe was likely established by the Mid Neolithic (~4000 BC), a substantial genetic contribution from subsequent pan-European cultures such as the Bell Beakers in the Late Neolithic (~2800 BC) may have contributed to its high modern day frequency.[21] The relationship between U152, Bell Beakers and mtDNA haplogroup H needs to be studied further. It is noteworthy that H1 is a North-East centered group that spreads southwards along the Apennines and H3 highlights the same North West – South East pattern observed for Y-chromosomes.
References: (see the link above)
A new study by Boattini et al. (2013) has made evident the high frequency of U152 in northern and central Italy (table 1).[1] This distribution has also been observed in prior studies.[2][3][4] For the first time however, we get a clearer picture of the U152′s intra-Italy regional frequency, and we can begin to infer some links to archaeological cultures.
http://r1b.org/wp-content/uploads/2013/06/U152_Only_Map.png
Table 1 – U152 frequency (Boattini et al. 2013)
There is a clear north-south gradient for U152 frequency, but it is slight from the Alps to central Italy and the drop-off accelerates in southern Italy. The tested areas with the highest U152 frequencies are Brescia (51.3%) and Cuneo (40%) in northern Italy, followed by Pistoia (38.5%) in Tuscany. Undifferentiated U152(xL2) has a frequency peak in Brescia and Pistoia (38.5%). If small commercial testing is any indication, Brescia’s U152(xL2) is made up largely of Z36 and to a lesser extent, Z56.[5] In Tuscany, Z36 shares its importance with Z56.[6] STR values of DYS385b ≥16 in U152* samples from LaSpezia/Massa (3 of 3) and Pistoia (2 of 5) might indicate high levels of Z56 subclade Z144/Z145/Z146.
L2(xL20) has its highest frequency in La Spezia/Massa (25.0%) and Treviso (24.2%) and L20 has its highest frequency in L’Aquila (3.3%), although if we look at the small pockets of L20 overall, it looks to be somewhat more common in the north than in the south. L2 as a percentage of overall U152 frequency reaches 39.2% on the Italian Peninsula, 25% in Sardinia and 20% in Sicily. This is in contrast to L2 outside of Italy (table 2). In Italy, L2 only makes up a majority of U152 lineages in the north-east region, and is highest in Treviso overall (80.0%). Unfortunately, subclades Z49 and Z367 were not tested in Boatinni’s L2(xL20) samples.
http://r1b.org/imgs/L2_Percentage_Table.png
Boattini et al. also ran Spatial Principal Component Analyses (sPCA) based on frequencies of Y-chromosome haplogroups. They found a three-partitioned structure of Italian population: 1) North-Western Italy (including most of the Padana plain and Tuscany.), 2) South-Eastern Italy and the whole Adriatic coast, and 3) Sardinia. Lineages contributing more to the differentiation along the first sPCA were R-U152*, and to a lesser extent, R-L2* and R-P312* in North-Western Italy, and G-P15 in South-Eastern Italy (Figure 1a), and I1-M26 in Sardinia (Figure 1b).
http://r1b.org/wp-content/uploads/2013/06/Boattini_sPCA.png
Figure 1. Spatial Principal Component Analysis (sPCA) based on frequencies of Y-chromosome haplogroups.
Copper Age Populations of Northern and Central Europe:
The results of Boattini’s age estimates suggest that most of the Y-chromosomal diversity present in modern day Italians was originated from few common ancestors living during late Neolithic times and the Early Metal Ages. Interestingly, the observed paternal population clusters are similar to dental (Figure 2) and cranial (Figure 3) morphological clusters of Italian Copper Age populations.[11][12] These show a close affinities between the Copper Age people of Northern and Center-West Italy. They also show a relationship between Southern Italian groups. While the Sardinian Copper Age groups are more similar to that of Southern Italy, they are still outliers when compared to all peninsular groups. If haplogroup U152 was already the differentiating Y-DNA group in Copper Age Northern and Central Italy, ancient Y-DNA studies should focus on finding it in the Remedello Culture (Brescia), the Spilamberto Group (Emilia-Romagna) and the Rinaldone Culture (Tuscany and northern Latium). Of particular interest is the Remedello Culture, which groups closely with Bell Beakers in cranial studies.[13]
http://r1b.org/wp-content/uploads/2013/06/Copper_Age_Dental_Traits_v002.png
Figure 2 – Dental traits of Copper Age Italian Populations
http://r1b.org/wp-content/uploads/2013/06/Copper_Age_Skulls_by_Region.png
Figure 3 – Cranial groupings of Italian Copper Age skulls
Ancient Y-DNA from Bell Beaker remains have been found to be R1b.[14] However, it is difficult to see Bell Beakers as a starting point for R1b in Italy, as there is substantial cultural and geographical continuity with the preceding Copper Age groups of Northern and Central Italy.[15] Given that, it is likely that a U152 presence in Italian Bell Beaker groups was the result of continuity from their immediate Copper Age predecessors. The influence of the Central European Bell Beaker Begleitkeramik group does seem to have made an impact in the formative phase of the Polada Culture in northern Italy and the late Bell Beaker period in Tuscany.[16][17] The changes brought on by the Polada Culture are so apparent that, by unanimous opinion, a movement of human groups has been presumed between Central Europe and the Po Valley.[18][19][20] The direction or origin of the gene flow is difficult to assess however. This Early Bronze Age phenomenon may explain why L2 as a percentage of U152 is highest in north-east Italy and makes up a larger amount of U152 outside of Italy.
While mtDNA haplogroup H in Europe was likely established by the Mid Neolithic (~4000 BC), a substantial genetic contribution from subsequent pan-European cultures such as the Bell Beakers in the Late Neolithic (~2800 BC) may have contributed to its high modern day frequency.[21] The relationship between U152, Bell Beakers and mtDNA haplogroup H needs to be studied further. It is noteworthy that H1 is a North-East centered group that spreads southwards along the Apennines and H3 highlights the same North West – South East pattern observed for Y-chromosomes.
References: (see the link above)