The Basques

Map showing the location of the Basque peopleThe Basque Region straddles the French-Spanish border between the curve of the Bay of Biscay and the lofty Pyrenees. The mountains capture the sea winds laden with moisture, which falls as rain all year round, keeping the Basque country green.

The Basques first appear in history as one people among many that the Romans fought in their conquest of Iberia. In the early first century AD Strabo describes the Ouaskonous living about the town of Pompelo and the coastal town of Oiasona.1Strabo, Geography, III, 4.10. About a century later the geographer Ptolemy too allocated the coastal Oeasso and a promentary of the same beside the Pyrénées to the Vascones, together with 15 inland towns, including Pompelon.2Ptolemy, Geography, II, 5: Tarraconensis Hispania. Pompelo/Pompelon is easily identified as Pamplona, Navarre. Oiasona/Oeasso presents more of a problem. While the name itself is preserved in Oyarzun in the Spanish Basque Country, 10 km to the east lies the border port of Irún, where a Roman harbour and other remains have been uncovered. Irún is a better fit to Ptolemy's description and is now the accepted identification of the Roman town. 3R.J.A. Talbert, Barrington Atlas of the Greek and Roman World (2000); J. Santos Yanguas, Identificación de las ciudades antiguas de Álava, Guipúzcoa y Vizcaya: Estado de la cuestión, Studia Historica: Historia Antigua, vol. 6 (1988), pp. 121-130; J.L. Ramirez Sádaba, Las ciudades Vasconas segun las fuentes literarias y su evolucion en la tardoantigüedad, Antigüedad y Cristianismo (Murcia), vol. 23 (2006), pp. 185-199.

As we shall see, there is reason to believe that this tribe was not alone in speaking the tongue which evolved into Euskara, the present-day language of the Basques. Across the border in what was then Gaul were the Aquitani, who spoke a language different from the Celtic-speaking Gauls. Strabo noted that they were more like the Iberes.4Strabo, Geography, book 4, chapter 2. Today the Basques are in the majority in the Basque Autonomous Community and the more mountainous parts of Navarre in Spain, and also live in the area of Bayonne and parts of Pyrénées Atlantiques, France.

Not so unusual

The idea that the Basques are a palaeolithic relic population was an attractive one in the days when population geneticists had only blood-groups to look at. Their high percentage of blood type O Rh-negative tied together with their non-Indo-European language made them seem a precious resource in efforts to understand the prehistory of Europe. The Basques have been a much-studied people. Studies have tended to find what they expected - something unusual about the Basques.5A Aguirre et al, Are the Basques a single and a unique population?, Science Genetics, vol. 49 (1991), no.2, pp. 450–458; M. Iriondo, M. C. Barbero and C. Manzano, MHUMF13A01 in autochthonous Basques and in genetically related populations, International Journal of Anthropology, vol. 16 (2001), no. 4, p. 225-233; I. Santin et al, Killer Cell Immunoglobulin-Like Receptor (KIR) Genes in the Basque Population: Association Study of KIR Gene Contents With Type 1 Diabetes Mellitus, Human Immunology, vol. 67 (2006), nos. 1-2, pp. 118-124.

After geneticists gained the sharper tools of mtDNA and Y-DNA they gradually realised that the Basques are not markedly different from any other European population in these ancestral markers.6F. Calafell et al, Genetic structure of the Spanish populations: the end of the Basque singularity? Paper read at the seventy-eight Annual Meeting of the American Association of Physical Anthropologists, 2009; S.Alonso, The place of the Basques in the European Y-chromosome diversity landscape, European Journal of Human Genetics, vol. 13, no. 12 (2005), pp. 1293-302. The common Western European Y-DNA haplogroup R1b1b2 (see Indo-European genetics) is as strongly represented in them as in their neighbours. So ingrained was the idea that Basque ancestry lay in the deep past, that the reaction was to declare that the whole population of Europe must descend from European hunter-gatherers. This nonsense continued up to, and even beyond, the point when Y-chromosome R1b1b2 was dated far too late for such a thesis to be feasible, but the tide turned with papers in 2010 recognising that the dominant strains in the European gene pool stem from Neolithic and later migrations. (See The genetic debate.)

One subclade of R1b1b2, identified by the marker M153, is found predominantly in Basques, but only about 10% of Basques carry it. It is therefore not a founding lineage, but a mutation that probably arose among the Basques, or entered their gene pool soon after its origin. Susan Adams actually found M153 at a higher level among a group of 24 testees from both the French and Spanish Pyrenees, whom she labelled Gascon. It was carried by 17% of them. M153 is sprinkled lightly across Iberia.7S. Alonso et al., The place of the Basques in the European Y-chromosome diversity landscape, European Journal of Human Genetics, vol. 13, no. 12 (2005), pp. 1293-1302; S.M. Adams et al, The Genetic Legacy of Religious Diversity and Intolerance: Paternal Lineages of Christians, Jews, and Muslims in the Iberian Peninsula, The American Journal of Human Genetics, vol. 83, no. 6 (December 2008), pp. 725-736. Elsewhere it seems restricted to those of Basque, Gascon or Iberian descent. That is the kind of distribution we would expect of a post-Roman mutation, which has not had the opportunity to travel widely except in the historic colonisation of the New World.

Much was made in early papers of the supposed absence in the Basque population of mtDNA J (a Neolithic marker). However more recent studies found a high frequency of haplogroup J in French and Spanish Basques, especially subhaplogroups J1c1 and J2a.8M.A. Alfonso-Sánchez et al., Mitochondrial DNA haplogroup diversity in Basques: A reassessment based on HVI and HVII polymorphisms, American Journal of Human Biology (2008); C. Richard et al, An mtDNA perspective of French genetic variation, Annals of Human Biology, vol. 34, (2007), issue 1, pp.:68-79. A high level of mtDNA J was also found in DNA extracted from 6th-7th century AD human remains at the necropolis of Aldaieta in the Spanish Basque Country.9Neskuts Izagirre, Genetic analysis of the historic necropolis of Aldaieta (Basque Country) and its implications in the evolutionary history of the Basques (2005): paper read at HUGO's 10th Human Genome Meeting.

Another popular theory was that the density of mtDNA haplogroups H1 and H3 in Iberia and particularly among the Basques reflects the Mesolithic re-colonisation of Europe from the Franco-Cantabrian glacial refuge. Yet the greatest diversity of H3 is in North Africa, and that for H1 in the Near East.10H. Ennafaa et al., Mitochondrial DNA haplogroup H structure in North Africa, BMC Genetics, vol.10, no. 8 (2009). That suggests that both arrived with early farmers. H1 and H3 show a low diversity in Cantabria and particularly among the Basques.11O. García et al., Using mitochondrial DNA to test the hypothesis of a European post-glacial human recolonization from the Franco-Cantabrian refuge, Heredity, vol. 106 (2011), pp. 37–45.

Also the Basques are 91.7% lactase persistent, a mutation connected to pastoralism.12N. S. Enattah et al, Evidence of Still-Ongoing Convergence Evolution of the Lactase Persistence T-13910 Alleles in Humans,The American Society of Human Genetics, vol. 81, no.3 (2007), pp.615-625. A genome-wide study of Spanish Basques did not find them particularly differentiated from other Iberian populations,13H. Laayouni, F. Calafell and J. Bertranpetit, A genome-wide survey does not show the genetic distinctiveness of Basques, Human Genetics, vol. 127 (2010), pp. 455–458. though a similar study redressed the balance somewhat by pointing out that French and Spanish Basques form an homogeneous group, which can be distinguished from non-Spanish European populations, to approximately the same degree that those populations (such as French and Sardinian) can be distinguished from each other.14N. Rodríguez-Ezpeleta et al., High-density SNP genotyping detects homogeneity of Spanish and French Basques, and confirms their genomic distinctiveness from other European populations, Human Genetics, vol. 128, no. 1 (2010), pp. 113-117. In short there is no evidence that the Basques are a living fossil of the original European gene pool.

Should we expect it? They have been surrounded by Indo-European speakers for millennia. Even a small gene flow, one percent per generation, into the Basque population from their neighbors for five thousand years, would replace ancient Basque genes.

But consider the languages spoken by these immigrants. Since they arrive in small numbers they and their children learn Basque and, save for occasional loan words, have little effect on the language. The Basque language has persisted over millenia while the neutral genome has been replaced. Meanwhile, natural selection at the Rh locus is such that the common type is favored. If the original state was all or mostly Rh negative, then there would ongoing selection against any Rh positive genes introduced by the immigrants. In this way, both language and the Rh system preserve deeper history than neutral genes.15H.C. Harpending and E. Eller, Human Diversity and its History, in M. Kato (ed.), The Biology of Biodiversity (1999), chapter 20, pp. 301–314.

Related languagues

Iberia c. 300 BC. Click to enlarge in new window The Basque language, Euskara, remains interesting as a non-Indo-European language. The late Larry Trask, an expert on Basque linguistics, dismissed the various attempts to connect Euskara to other languages, with one exception. It seems clear that Aquitanian was an ancestral form of Euskara. Aquitanian was spoken in south-western Gaul. South of the Pyrenees the only evidence for Aquitanian/Euskara in Roman times is three inscriptions found in eastern Navarre, an area associated by Strabo with a tribe called Vascones. There is no sign of Basque place-names in what is now the Spanish Basque Country in the early Roman period. So it appears that the language spread into these territories after the collapse of Roman power there.16R.L. Trask, Origin and relatives of the Basque language: a review of the evidence, in J.I. Hualde, J.A. Lakarra, R. L. Trask (eds.), Towards a History of the Basque Language (1995), pp. 65-99; R. L. Trask, The History of Basque (1997), chapter 6. Other supporters of this hypothesis, known as the late basquenization of the Basque depression, have dated the migration to the 6th and 7th centuries.17F. Villar, B. M. Prósper,Vascos, Celtas e Indoeuropeos: Genes y lenguas (2005), p.513.

The Basques are not the only unexplained anomaly in Iberia. The Iberians too spoke a non-Indo-European language. It has been generally assumed that the Iberians predated the Celts in Iberia. Yet the southeastern territory in which Iberian was once spoken has just as much Y-chromosome R1b1b2 + in its present-day population as the areas which were Celtic-speaking. Who were the Iberians? There has been much debate about their long dead language, which remains largely undeciphered. Painstaking work over recent decades has uncovered similarities with Aquitainian. Even if we argue that these similarities were the result of linguistic borrowing, rather than a common ancestor, the two would need to be in contact for borrowing to take place.

The idea that Iberian might originally have been spoken outside Iberia is startling. Yet Rodriguez Ramos has suggested just that. Inscriptions in Iberian have been found along the broadly coastal strip from the Languedoc in Southern France to Almeria in South-East Spain. That more or less coincides with the intrusion into Iberia of the early Iron Age Urnfield Culture. This is considered a precursor to the Celtic cultures of Central Europe. Yet Ramos argues that some of the people on the move at this time might have spoken a different language from the rest. However Javier Veleza points to the homogeneity of Iberian c. 400 BC, when the first inscriptions occur. A language that had arrived in that whole territory with the Urnfield Culture would have had centuries in which to diverge into dialects. A more plausible alternative is that Iberian had spread later - south and along the coast from a homeland bordering Aquitanian.18J. Veleza, Lengue vs. cultura material: el (viejo) problema de la lengua indigena de Catalunya, Actes de la III Reunió Internacional d'Arqueologia de Calafell (Calafell, 25 al 27 de novembre de 2004), Arqueo Mediterrània, vol. 9 (2006), 273-280.

Another lost language appears to tie Euskara and Iberian together. Today the people of Sardinia speak a Romance language, a legacy of the Roman Empire. Their pre-Roman language lasted longest in the interior of the island. Eduardo Blasco Ferrer has analysed field names in this archaic central area of Sardinia. He finds many relationships to paleo-Basque and paleo-Iberian. Controversially he considers that this reflects a migration from Iberia to Sardinia dating back to the Mesolithic period.19E. Blasco Ferrer, Paleosardo: Le radici linguistiche della Sardegna neolitica (2010). Hunter-gatherers did indeed disperse from an Ice Age refuge in Iberia, but they made little impact on Sardinia. Sardinian obsidian found outside the island has been taken as proof of its trade by hunter-gatherers, yet little of it can be dated before the Neolithic.20S. L. Dyson and R.J. Rowland, Archaeology and history in Sardinia from the Stone Age to the Middle Ages: shepherds, sailors and conquerors (2007), pp. 24-32. So it seems more likely that any connection with Iberia came later.

Larry Trask admitted that there is a similarity between Euskara and Proto-Indo-European which cannot be dismissed linguistically. Antonio Tovar argued that the suffix -ko in Basque is so similar in its behaviour to the same suffix reconstructed for PIE that they must have a common origin. Since Trask took it for granted that Euskara had developed in Western Europe, while PIE developed far from there, he could make no sense of this.21R.L. Trask, Origin and relatives of the Basque language: a review of the evidence, in J.I. Hualde, J.A. Lakarra, R. L. Trask (eds.), Towards a History of the Basque Language (1995), pp. 65-99 (74-75). Yet if we abandon the idea that Euskara developed in Western Europe, it may make a great deal of sense.

Neolithic arrival?

Spread of Neolithic Impressed WareIt seems doubtful that any European Mesolithic language survived the incoming wave of farmers and thousands of years in which they consolidated their hold on Europe. The pattern world-wide appears to be that the languages of hunter-gatherers were replaced by those of farmers.22J. Diamond and P. Bellwood, Farmers and Their Languages: The First Expansions, Science, vol. 300 (2003), no. 5619, pp. 597-603. So the non-Indo-European languages which survived long enough to be written down or mentioned by Classical authors were probably all Neolithic period or later arrivals.

Distribution of haplogroup Y-DNA I2a1The permanent settlement of Sardina seems to start with farmers making Cardial pottery - a type of Impressed Ware.23S. L. Dyson and R.J. Rowland, Archaeology and history in Sardinia from the Stone Age to the Middle Ages: shepherds, sailors and conquerors (2007), pp. 24-32. The trail of Cardial Ware springs from the Near East to the Adriatic and then spreads around the northern coast of the Mediterranean. From the Golfe du Lion it travelled via the Aude and the Carcassone Gap into the valley of the Garonne,24B. Cunliffe, Europe Between the Oceans (2008), pp.115-6. where millennia later Romans encountered tribes speaking Aquitanian. John Bengtson argues on linguistic evidence that the ancestor of Basque arrived along with the Cardial culture. He points out that Basque vocabulary includes words for domestic animals, domesticated plants, and implements used in food production, which have cognates in North-West Caucasian languages. There are also a few borrowings from Near Eastern Afroasiatic languages, Egyptian and Semitic. Flying in the face of the scepticism of the late Larry Trask about attempts to fit Basque into a family with other living languages, Bengtson deduces that there was a common ancestor of Basque and the North Caucasian group. He calculates that the two branches parted ways around 6,880 BC.25J. D. Bengtson, The Basque Language: History and Origin, International Journal of Modern Anthropology, vol. 4 (2011), pp. 43 - 59.

While this would not necessarily require a genetic similarity between the populations of the Caucasus and the present-day Basques, it is discouraging that there is so little correspondence. Kristin Young and her colleagues compared autosomal short tandem repeat (STR) data from Basque individuals living in 27 mountain villages with that of neighboring populations in Europe, as well as one group from the Caucasus. They found no support for the hypotheses of a recent common ancestor between the Basques and populations from the Caucasus. Their finding is in line with those of previous studies which they cite, revealing no genetic commonality between Basques and peoples of the Caucasus.26K.L. Young et al, Autosomal short tandem repeat genetic variation of the Basques in Spain, Croatian Medical Journal, vol. 52, no. 3 (June 2011), pp. 372–383. Their sampling in the Caucasus was admittedly perfunctory, but a detailed study of the correspondence between language and Y-DNA in the North Caucasus is enlightening. Each language group correlates with a specific haplogroup. For the North-Western group the characteristic haplogroup is G2a3b1-P303.27O. Balanovsky et al., Parallel Evolution of Genes and Languages in the Caucasus Region, Molecular Biology and Evolution, Advance Access published May 13, 2011. This haplogroup does not appear among the Basques.

The western part of the Cardial distribution coincides with that of Y-DNA haplogroup I2a1a-M26. This haplogroup is rare outside Sardinia, where it represents about 40% of the Y-DNA. That suggests a founder effect. I2a1 looks like a clade that sprang from I2a assimilated by farmers in South-Eastern Europe, which moved westward with a group of Impressed Ware people. If so, then the most likely place for Impressed Ware makers from the Near East to take on board a man carrying I2a would be Western Anatolia. (See The Story of I). I2a1 is not unknown among the Basques, if we assume that the 11% of haplogroup I found in the Spanish Basques was mainly I2a1 (a large assumption). However it is far from the predominant haplogroup.28S.M. Adams et al, The Genetic Legacy of Religious Diversity and Intolerance: Paternal Lineages of Christians, Jews, and Muslims in the Iberian Peninsula, The American Journal of Human Genetics, vol. 83, no. 6 (December 2008), pp.725-736.

Copper or Bronze Age arrival?

An alternative proposal would be that the Basques and Iberians descend from a small group that arrived along with the wave of Indo-European colonisation, but happened to speak a different language. The early speakers of Proto-Indo-European seem to have mixed with their neighbours and peoples encountered as they spread. No doubt the mixing could be in the form of male Indo-European speakers taking wives who spoke another language. If the male then died, leaving a mother to bring up her children within the Indo-European community, yet teaching her children her own mother-tongue, we can see how the oddity that is the Basques might arise.

The suggested route of Proto-Italo-Celtic-speaking stelae makers. Click to enlarge in new windowOr should we picture a multi-lingual Copper and Bronze Age migration into Iberia? The latter is feasible. Adjoining the Pontic-Caspian steppe, where it is deduced that the Proto-Indo-European language developed, were the farmers and pastoralistists of the Cucuteni-Tripolye Culture, some of whom seem to have been eventually assimilated by the Yamnaya Culture of the steppe. If Y-DNA haplogroup R1b1b2 + entered the region with the Cucuteni-Tripolye Culture, then it is perfectly possible for it to have been carried by speakers of both PIE and the original language of Cucuteni-Tripolye.

This would explain why Euskara appears to be a language from the age of metal. It includes indigenous Basque words relating to agriculture, wheeled vehicles and metallurgy, such as shepherd (artzain), millet (artatxiki - formerly arto), wine (ardo), cart (gurdi), wheel (gurpil from *gurdi-bil, meaning cart-round), smith ([h]arotz), iron (burdina), lead (berun), gold (urre), and silver (zillar or urre-zuri - literally white gold). 29R. L. Trask, Etymological Dictionary of Basque, edited for web publication by Max W. Wheeler (2008), pp. 102, 110, 137, 142, 148, 212, 360. If Euskara were originally the language of hunter-gatherers of South-West Europe, one would expect it to have borrowed words relating to agriculture and metallurgy. A common pattern, where a people adopt a new technology from those speaking another language, is for the foreign words for that technology to be borrowed at the same time. Oddly the most common Basque words for tin (eztainu), copper (kobre) and bronze (brontze) are all borrowed from Romance. However Euskara originally had its own words for these metals. 30S.F. Pushkariova, Primario e secundario en los nombres vascos de los metales, Fontes linguae vasconum: Studia et documenta, vol. 30, no.79 (1998), pp. 417-428. Thanks to Iñaki Arrizabalaga for pointing this paper out and other linguistic comments.

The fact that one word for silver was derived from the word for gold suggests a region where gold was discovered first. That points to the eastern Balkans, and cultures such as Cucuteni-Tripolye. The Ozieri Culture which sprang up in Sardinia c. 4000 BC has much in common with that of Cucuteni-Tripolye. Thus we can perceive a possible route for Proto-Basque from Ukraine via the Black Sea to Sardinia and from there up the Garonne to Aquitaine. However there seems a complete lack of archaeological evidence for that latter stage of the journey, and the similarity of Cucuteni-Tripolye and Ozieri is by no means established fact.

Conclusion

It seems most likely that the Basques descend from a Copper Age group drawn to the Pyrenees by its copper resources, though the evidence for any particular place of origin is too slight to build upon. The Basques remain something of a mystery. Only studies of ancient DNA in Aquitaine and the Pyrenees seems likely to resolve it.

Notes

If you are using a browser with up-to-date support for W3C standards e.g. Firefox, Google Chrome, IE 8 or Opera, hover over the superscript numbers to see footnotes online. If you are using another browser, select the note, then right-click, then on the menu click View Selection Source. If you print the article out, or look at print preview online, the footnotes will appear here.

  1. Strabo, Geography, III, 4.10.
  2. Ptolemy, Geography, II, 5: Tarraconensis Hispania.
  3. R.J.A. Talbert, Barrington Atlas of the Greek and Roman World (2000); J. Santos Yanguas, Identificación de las ciudades antiguas de Álava, Guipúzcoa y Vizcaya: Estado de la cuestión, Studia Historica: Historia Antigua, vol. 6 (1988), pp. 121-130; J.L. Ramirez Sádaba, Las ciudades Vasconas segun las fuentes literarias y su evolucion en la tardoantigüedad, Antigüedad y Cristianismo (Murcia), vol. 23 (2006), pp. 185-199.
  4. Strabo, Geography, book 4, chapter 2.
  5. A. Aguirre et al, Are the Basques a single and a unique population?, American Journal of Human Genetics, vol. 49, no.2 (1991), pp. 450–458; M. Iriondo, M. C. Barbero and C. Manzano, MHUMF13A01 in autochthonous Basques and in genetically related populations, International Journal of Anthropology, vol. 16 (2001), no. 4, p. 225-233; I. Santin et al, Killer Cell Immunoglobulin-Like Receptor (KIR) Genes in the Basque Population: Association Study of KIR Gene Contents With Type 1 Diabetes Mellitus, Human Immunology, vol. 67 (2006), nos. 1-2, pp. 118-124.
  6. F. Calafell et al, Genetic structure of the Spanish populations: the end of the Basque singularity? Paper read at the seventy-eight Annual Meeting of the American Association of Physical Anthropologists, 2009; S. Alonso, The place of the Basques in the European Y-chromosome diversity landscape, European Journal of Human Genetics, vol. 13, no 12 (2005), pp.1293-302.
  7. S. Alonso et al., The place of the Basques in the European Y-chromosome diversity landscape, European Journal of Human Genetics, vol. 13 (2005), pp. 1293–1302; S.M. Adams et al, The Genetic Legacy of Religious Diversity and Intolerance: Paternal Lineages of Christians, Jews, and Muslims in the Iberian Peninsula, The American Journal of Human Genetics, vol. 83, no. 6 (December 2008), pp. 725-736.
  8. M.A. Alfonso-Sánchez et al., Mitochondrial DNA haplogroup diversity in Basques: A reassessment based on HVI and HVII polymorphisms, American Journal of Human Biology (2008); C. Richard et al, An mtDNA perspective of French genetic variation, Annals of Human Biology, vol. 34, (2007), issue 1, pp.:68-79.
  9. Neskuts Izagirre, Genetic analysis of the historic necropolis of Aldaieta (Basque Country) and its implications in the evolutionary history of the Basques (2005): paper read at HUGO's 10th Human Genome Meeting.
  10. H. Ennafaa et al., Mitochondrial DNA haplogroup H structure in North Africa, BMC Genetics, vol.10, no. 8 (2009).
  11. O. García et al., Using mitochondrial DNA to test the hypothesis of a European post-glacial human recolonization from the Franco-Cantabrian refuge, Heredity, vol. 106 (2011), pp. 37–45.
  12. N. S. Enattah et al, Evidence of Still-Ongoing Convergence Evolution of the Lactase Persistence T-13910 Alleles in Humans,The American Society of Human Genetics, vol. 81, no.3 (2007), pp.615-625.
  13. H. Laayouni, F. Calafell and J. Bertranpetit, A genome-wide survey does not show the genetic distinctiveness of Basques, Human Genetics, vol. 127 (2010), pp. 455–458.
  14. N. Rodríguez-Ezpeleta et al., High-density SNP genotyping detects homogeneity of Spanish and French Basques, and confirms their genomic distinctiveness from other European populations, Human Genetics, vol. 128, no. 1 (2010), pp. 113-117.
  15. H.C. Harpending and E. Eller, Human Diversity and its History, in M. Kato (ed.), The Biology of Biodiversity (1999), chapter 20, pp. 301–314.
  16. R.L. Trask, Origin and relatives of the Basque language: a review of the evidence, in J.I. Hualde, J.A. Lakarra, R. L. Trask (eds.), Towards a History of the Basque Language (1995), pp. 65-99; R. L. Trask, The History of Basque (1997), chapter 6.
  17. F. Villar, B. M. Prósper, Vascos, Celtas e Indoeuropeos: Genes y lenguas (2005), p.513.
  18. J. Veleza, Lengue vs. cultura material: el (viejo) problema de la lengua indigena de Catalunya, Actes de la III Reunió Internacional d'Arqueologia de Calafell (Calafell, 25 al 27 de novembre de 2004), Arqueo Mediterrània, vol. 9 (2006), 273-280.
  19. E. Blasco Ferrer, Paleosardo: Le radici linguistiche della Sardegna neolitica (2010).
  20. S. L. Dyson and R.J. Rowland, Archaeology and history in Sardinia from the Stone Age to the Middle Ages: shepherds, sailors and conquerors (2007), pp. 24-32.
  21. R.L. Trask, Origin and relatives of the Basque language: a review of the evidence, in J.I. Hualde, J.A. Lakarra, R. L. Trask (eds.), Towards a History of the Basque Language (1995), pp. 65-99 (74-75).
  22. J. Diamond and P. Bellwood, Farmers and Their Languages: The First Expansions, Science, vol. 300 (2003), no. 5619, pp. 597-603.
  23. S. L. Dyson and R.J. Rowland, Archaeology and history in Sardinia from the Stone Age to the Middle Ages: shepherds, sailors and conquerors (2007), pp. 24-32.
  24. B. Cunliffe, Europe Between the Oceans (2008), pp.115-6.
  25. J. D. Bengtson, The Basque Language: History and Origin, International Journal of Modern Anthropology, vol. 4 (2011), pp. 43 - 59.
  26. K.L. Young et al, Autosomal short tandem repeat genetic variation of the Basques in Spain, Croatian Medical Journal, vol. 52, no. 3 (June 2011), pp. 372–383.
  27. O. Balanovsky et al., Parallel Evolution of Genes and Languages in the Caucasus Region, Molecular Biology and Evolution, Advance Access published May 13, 2011
  28. S.M. Adams et al, The Genetic Legacy of Religious Diversity and Intolerance: Paternal Lineages of Christians, Jews, and Muslims in the Iberian Peninsula, The American Journal of Human Genetics, vol. 83, no. 6 (December 2008), pp. 725-736.
  29. R. L. Trask, Etymological Dictionary of Basque, edited for web publication by Max W. Wheeler (2008), pp. 102, 110, 137, 142, 148, 212, 360.
  30. S.F. Pushkariova, Primario e secundario en los nombres vascos de los metales, Fontes linguae vasconum: Studia et documenta, vol. 30, no.79 (1998), pp. 417-428. Thanks to Iñaki Arrizabalaga for pointing this last paper out and other linguistic comments.