Ancient DNA from Hunter-Gatherer and Farmer Groups from Northern Spain Supports a Random Dispersion Model for the Neolithic Expansion into Europe

Hervella et al. 2012

Samples : 

Haplogroups :

Haplogroup H is the major one, showing a frequency of 45% in the ancient samples analysed. This figure is similar to that observed in some present-day European populations including the North of the Iberian Peninsula

Two of the Palolithic hunter-gatherer from Cantabria belong to mtDNA H .

The three groups of hunter-gatherers considered in this analysis (from Scandinavia, Central Europe and the Cantabrian fringe on the Iberian Peninsula) did not show statistically significant differences between one another, but they are significantly different from any population compared, because to the high frequency of haplotypes within the haplogroup U (50%–80%) .

Abstract

Background/Principal Findings

The phenomenon of Neolithisation refers to the transition of prehistoric populations from a hunter-gatherer to an agro-pastoralist lifestyle. Traditionally, the spread of an agro-pastoralist economy into Europe has been framed within a dichotomy based either on an acculturation phenomenon or on a demic diffusion. However, the nature and speed of this transition is a matter of continuing scientific debate in archaeology, anthropology, and human population genetics. In the present study, we have analyzed the mitochondrial DNA diversity in hunter-gatherers and first farmers from Northern Spain, in relation to the debate surrounding the phenomenon of Neolithisation in Europe.

Methodology/Significance

Analysis of mitochondrial DNA was carried out on 54 individuals from Upper Paleolithic and Early Neolithic, which were recovered from nine archaeological sites from Northern Spain (Basque Country, Navarre and Cantabria). In addition, to take all necessary precautions to avoid contamination, different authentication criteria were applied in this study, including: DNA quantification, cloning, duplication (51% of the samples) and replication of the results (43% of the samples) by two independent laboratories. Statistical and multivariate analyses of the mitochondrial variability suggest that the genetic influence of Neolithisation did not spread uniformly throughout Europe, producing heterogeneous genetic consequences in different geographical regions, rejecting the traditional models that explain the Neolithisation in Europe.

Conclusion

The differences detected in the mitochondrial DNA lineages of Neolithic groups studied so far (including these ones of this study) suggest different genetic impact of Neolithic in Central Europe, Mediterranean Europe and the Cantabrian fringe. The genetic data obtained in this study provide support for a random dispersion model for Neolithic farmers. This random dispersion had a different impact on the various geographic regions, and thus contradicts the more simplistic total acculturation and replacement models proposed so far to explain Neolithisation.

R-L21 in Northern Spain

The study of Martínez-Cruz et al. 2012 shows a distribution of Y-DNA haplgroups from Basques and surrounding regions, from Spain and France. My focus is on the sublcade of R1b , R-L21, which is most common in the British Isles and Brittany, and until now it has not been much tested for in Iberia.
In some regions of Spain tested in this study it surpasses 20% of frequency.  Here is the table for all haplogorups and samples. The regions corresponding to Spain and their R-L21 frequency are :

Southwestern Gipuzkoa, n = 13/57 = 22.81%
Roncal Valley, Navarra: n = 11/53 = 20.8 %
Alaba, n = 11/51 = 21.57%
Guipuzkoa, n = 9/47 = 19.15%
Central/Western Navarra, n = 9/60 = 15.0%
Bizkaia, Basque Country, n = 7/57 = 12.28%
La Rioja, n = 6/54 = 11.11 %
Western Bizkaia , n = 3/19 = 10.53%
Northwestern Navarra, n = 5/51 = 9.80%
Northern Aragón : n = 1/27 = 3.7%

Total : n = 75/476 = 15.76%

mtDNA L in Europe and Spain

Here is a compilation from many different studies, for the frequencies of the maternal Sub-Saharan haplogroup mtDNA L,  for countries from all around  Europe. At the bottom, there is a compilation for the total of Spain. We'll see that spanish percentages are similar to other countries and/or regions of Europe. 

For some obscure reasons, on the Wikipedia articles  "mtDNA L in Europe", and  "African admixture in Europe" there is only  Iberia and Italy as european countries having mtDNA L, we will see here that this is not the case, there is in all corners of the continent. And I advise you if you dare to edit those articles,  you'll probably get blocked.


Slovaks              n = 2/207    0.97%      Malyarchuk et al.2006

Czechs              n = 1/279     0.36%      Malyarchuk et al., 2008

German-Danish  n = 1/161     0.62%      Richards et al. 1996
Germany            n = 1/335     0.30%      Achilli et al 2007
Germany            n = 4/333    1.20%      Pliss et al. 2005

Albania             n =  1/42      2.38%     Belledi et al. 2000
Bosnia             n=1/144        0.70%    Achilli et al 2007
Bulgaria           n=1/141        0.71%    Achilli et al 2007
Balkans          n= 1/556        0.18%    Regueiro et al. 2012 + King et al. 2011


Poland              n = 1/542     0.20%      Achilli et al 2007
Poland              n = 1/436     0.22%      Malyarchuk et al., 2002
Poles                n = 1/849     0.12%      Malyarchuk et al., 2008


British               n=1/100      1.00%      Piercy et al. 1993
England            n = 2/335     0.60%      Achilli et al 2007
England            n  = 1/142    0.70%     Helgason et al., 2001
Great Britain     n = 1/114     0.90 %     García et al. 2011
Scotland           n = 1/891     0.10 %     García et al. 2011


Finnish             n = 1/50       2.00%     Sajantila et al. 1995
Finland            n = 1/121     0.83%     Achilli et al 2007
Finns               n = 3/580     0.52%     Pliss et al. 2005


Norway          n = 1/74       1.40%     Passarino et al 2002
Norwegians    n = 2/397     0.50%      Pliss et al. 2005


Russia            n =  2/683     0.29%     Malyarchuk et al. 2008


France            n = 1/332      0.30%    Achilli et al 2007
France            n = 5/692      0.72%     Richards et al. 2007
France            n =  3/433     0.69%     García et al. 2011
France            n = 2/320      0.63%     Pliss et al. 2005
France                                 1.40%     Gónzalez et al. 2003


Switzerland      n=1/228        0.44%    Achilli et al 2007


Crete, Greece  n= 2/202       0.99%    Achilli et al 2007


Italy                n = 8/411      1.94%     Plaza et al. 2003,  Romano et al. 2003

NW Italy         n = 100        2.00%    Brisighelli et al. 2012

Sardinian         n = 2/69       2.90%     Di Rienzo and Wilson 1991
Sardinia          n =2/370       0.54%    Achilli et al 2007

Sicily               n= 1/106       0.94%     Cali et al. 2001
Sicily               n = 2/105      1.90%     Achilli et al 2007
Sicily              n = 3/465       0.65%    Plaza et al. 2003,  Romano et al. 2003
South Italy     n = 2/313        0.64%    Boattini et al. 2013 + Stefania Sarno et al. 2014

Tuscany          n= 6/322        1.86%    Achilli et al 2007
Marche (Italy) n=8/813         0.98%    Achilli et al 2007
Latium(Italy)    n=4/138        2.90%    Achilli et al 2007
Murlo (Italy)    n = 1/86       1.16%     Achilli et al 2007
Volterra (Italy) n =  3/114     2.63%    Achilli et al 2007
Casentino (Italy) n =  2/122  1.64%   Achilli et al 2007
Campania        n = 3/313      0.32%   Achilli et al 2007



Spain Total   n = 51 / 4.329     1.18%    From here :

Spain   n = 15/813   1.84%       Achilli et al 2007
Spain,  n =  0/686    0.00%       Rhouda 2006
Spain   n =  0/233    0.00%,      Lopez-Parra 2009
Spain   n =  1/251    0.40%       Plaza et al. 2003
Spain   n =  9/312    2.90%       Álvarez et al. 2007
Spain   n =  1/108    0.90%       Casas et al. 2006 *
Spain   n =  2/226    0.88%       Maca-Meyer et al. 2003
Spain   n = 15/742   2.02%      García et al. 2011
Spain (Basques)  n = 0/462      García et al. 2011
Spain, Zamora Province**  n =10/214    4.67%      Álvarez  et al. 2010
Spain, n = 8/496     1.61%       Pereira et al. 2005

Note that in the García et al. 2011 there is overlapping with other studies, that's why the total shown here  is not the same as the total you might get from the study.

- * Note that Casas et al. 2006 only considered L1-L2 sequences to be of sub-Saharan origin.
-** This study inlcudes only a sample from a small town of the province of Zamora, thus it is not very representative of the population of Spain, I prefer wider regions, anyways I have included them.
- Note about the subclade L3, some scholars don't consider it as Sub-Saharan (Maca-Meyer 2003 et al.) in her words :
""L3 is more related to Eurasian haplogroups than to the most divergent African clusters L1 and L2". L3 is the haplogroup from which all modern humans outside of Africa derive"

Total E-M81 in Spain

UPDATE (13/03/2012) : Added the samples from Martínez-Cruz et al. 2012, which includes Navarrese, Burgos (Castilla),  La Rioja and Cantabria.

Spanish Basques     n=2/55    3.6%    Cruciani 2004.
Basques                  n=1/45    2.2%    Underhill 2000. 
Basque Country      n=1/116  0.9%    Adams et al.
Basques                 n=1/168   0.6%    Capelli 2009 (Alonso et al. + Garcia et al)
Basques                  n=1/43    2.3%    Capelli 2009 from Bosch et al.
------------
Total Basques  6/427 = 1.4%


Navarra, Cinco Villas       n=0/42    0.0%       López-Parra 2009
Lapurdi, Navarra              n =0/66   0.0%       Martínez-Cruz et al. 2012
Central/Western Navarra  n = 1/60  1.7%       Martínez-Cruz et al. 2012
Northwestern Navarra     n = 0/51   0.0%       Martínez-Cruz et al. 2012
Valle Roncar, Navarra     n = 2/53   3.77%     Martínez-Cruz et al. 2012
 ------
Total Navarra :   3/272 = 1.10%


Pasiegos*               n=15/64     24%        Maca-Meyer 2003.
Lebaniegos             n=0/37       0.0%       Maca-Meyer 2003.
Other Cantabrians   n=6/36      16.7%      Maca-Meyer 2003.
Cantabria               n=17/161   13.0%      Brión et al. 2004
Cantabria               n=1/18        5.56%     Martínez-Cruz et al. 2012
--------
Total Cantabria      n=39/316 = 12.23%


La Rioja,   n = 0/54      0.0%                 Martínez-Cruz et al. 2012
 

Asturians             n=2/90       2.2%       Cruciani 2004.
Asturias              n=0/20       0.0%       Adams et al.   
-----------
Total Asturias      n=2/110 = 1.82%


Aragón                   n=3/34    8.8%     Adams et al.
Aragón, Jacetania   n=0/31    0.0%     López-Parra 2009
Northern Aragón    n =0/27   0.0%     Martínez-Cruz et al. 2012 
------------------
Aragón :  3/92  3.26 %
  

Galicia             n=2/19      10.5%    Flores et al.2004
Galicia             n=9/88      10.2%    Adams et al. 2008
Galicia             n=12/292    4.1%    Brión et al.2004
--------
Total Galicia    23/399= 5.76%


Valencia            n=2/31     6.5%       Flores et al.2004
Valencia            n=4/73     5.48%    Adams et al.
----------
Total Valencia   6/104 = 5.77%


Castille                  n=1/21     4.8%     Flores et al.2004
Burgos                  n =1/20    5.0%     Martínez-Cruz et al. 2012
Castilla Mancha     n=2/63     3.2%    Adams et al.
Castile NE            n=3/31      9.7%    Adams et al.
Castille NW          n=10/100 10.0%   Adams et al.
----------
Total Castilla   17/235 = 7.23%


Catalans            n=0/16     0.0%     Bosch et al.2001
Catalonia           n=1/80    1.25%   Adams et al.
Vall d'Arán         n=1/25    4.00%   López-Parra 2009
Cerdeña             n=0/37    0.00%   López-Parra 2009
Alt Urgell          n=0/34    0.00%   López-Parra 2009
-----------
Total Catalonia  2/192 = 1.04%


Extremadura         n=4/52   8.0%   Adams et al.
-----------

Majorca             n=2/62    3.22%    Adams et al.
Minorca             n=3/37    8.1%      Adams et al.
Ibiza                 n=0/54     0.0%      Adams et al.
----------
Balearic Islands : 5/153 = 3.27%


Southern Spaniards   n=1/62      1.6%     Scozzari 2001.
Huelva, Andalusia     n=5/167   2.99%    Ambrosio 2010.
Huelva, Andalusia     n=1/22      4.5%     Flores et al.2004
Seville, Andalusia     n=7/155     4.5%     Flores et al.2004
Cadiz, Andalusia      n=0/28       0.0%     Flores et al.2004
Cordoba, Andalusia  n=2/27      7.4%     Flores et al.2004
Malaga, Andalusia   n=3/26     11.5%     Flores et al.2004
Andalusia East         n=2/95      2.1%     Adams et al.
Andalusia West       n=10/73    13.7%    Adams et al.
Andalusians           n=2/37        5.4%     (Capelli 2009)  Bosch et al.
------------------
Total Andalusia :  33/692 = 4.77%

TOTAL SPAIN =   143/3.098 =  4.62 %

*without Pasiegos = 128/3034 = 4.22 %

Canarians were not included for obvious reasons.


Observations :

- We obtain a result of between 4 and 5%, slightly lower than that observed for Portugal (5.73%).

- The closest spanish region to the national average would be Andalusia (4.77%).

- As mentioned before, I reiterate the lack of correlation between islamic history in Iberia and these subclade frequencies, such that Andalusia (the place were Islamic religion lasted longer, specifically Western Andalusia) has less E-M81 than some northern regions such as Galicia, Cantabria, Valencia, Castille, which essentially means the presence of this subclade in Iberia has very little to do with the islamic period, in other words, the moors (in the ethnic sense)  had a very minoritary presence in Spain.

- Another obersvation I make, is the difference between Galicia and it's close neighbour Asturias, which has amongst the lowest frequency of the spanish communities.

- The lowest presence is in Catalonia, with aprox. 1%,  followed by Basques (1.4%) and the highest in Cantabria (12.75% with Pasiegos, 9.8% without Pasiegos).

- Obviously the samples of the various communities are still very small and unrepresentitative, so this percentages are only orientative.

- Compared to other nations, the closest country besides Portugal in terms of similar percentages, would be France, with 4.42 % (see here).

Total E-M81 in Portugal

Southern Portuguese  n=6/49   12.2%   Cruciani 2004.
Southern Portugal      n=6/78  8.00%   Adams et al.
South Portugal          n=6/100   6.0%   Goncalves 2005
Total South :   20/257 = 7.8%

Central Portugal    n=5/102   4.9%   Goncalves 2005

Northern Pprtuguese   n=2/50    4.0%    Cruciani 2004.
Northern Portuguese    n=6/109   5.5%   Flores et al.
Northern Portugal        n=2/60    3.0%    Adams et al.
North Portugal            n=6/101   5.9%   Goncalves 2005
Total North :  17/320 = 5.3%

Portugal               n= 33/659  5.0%   Capelli et al. 2009 (includes Beleza et al.)

Total Portugal (all samples)  n = 70 / 1.308 = 5.35%

Very similar to the percentage of Galicia (5.76%) and below 6% again when considering many studies. This percentage is similar to some areas of France ( like Auvergne ( 5.62%,  Cruciani 2004), and the North of Portugal has higher than spanish southern region of Andalusia (4.7% see my previous entry). I will publish another entry with the total for Spain.

E-M81 in Galicia

Total of E-M81 in Galicia (NW Spain), considering many studies :

Galicia             n=2/19    10.5%    Flores et al.2004
Galicia             n=9/88    10.2%    Adams et al.
Galicia             n=12/292   4.1%    Brion et al.2004
--------
Total Galicia    23/399= 5.76%

It's actually below 6% when combining different studies, and similar to those found in some areas of France, like Auvergne ( 5.62%,  Cruciani 2004), and higher than those found in Andalusia (4.7% , see here). This presence is obviously due to pre-historic migration, because muslim history in Iberia doesn't correlate with genetics, as seen here, when Andalusia has less E-M81 than some northern spanish communities.