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Until 2012 none of the genetic studies incorporated samples from all seven Euskal Herria provinces and proximal lands, where a Basque language
was probably spoken during historical times. Euskal Herria "might" have at one time extended from the Garonne River in the north to the Erbo River in the south [equivocal]. Basque language inscriptions and speech remnants have been identified outside of historical Euskal Herria [Gorrochategui,1995]. The theonyms, some place and personal names suggest that the ancient residents of Aquitania could have conversed in a proto-Basque tongue [B Martinez-Cruz,2012].
The Basque inhabit rugose terrain in the SW extremity of France and adjacent Spain, which is composed of seven provinces. During the last glacial era the polar front reached the Pyrenees and temperatures are estimated to have been about 15 degrees C below today's average levels. The unfavourable climatic conditions probably fragmented northern Iberian populations and limited gene flow between these groups, which subsequently could have been partially perpetuated by the rugged topography over a portion of the Basque Lands.This premise is compatible with the eight distinct regional Euskera dialects, that are spoken by the Basques [de Yrizar].These lands are called Euskal Herria, the landof the Euskera speakers. It is their unique, ancient, non-Indo-European, agglutinating language, which identifies the Basques, who have a high frequency of Rh negative blood [ca 25%].No linguistic equivalent to their language has been found. The origin of this tongue is unknown. A proto-type "might" have been introduced to the Basque lands by people, who predated the influx of Neolithic agriculturalists, who "may" have spoken an Indo-European language [speculation].
Preservation of the Basque identity contrasts sharply with the physical, but not genetic, disappearance of the Neanderthals. The sparse scatterings of small Neanderthal groups were not able to cope with the appreciable influxes of Homo sapiens. The Basques were largely concentrated in a relatively rugged region and large tracts of their land were not prime agricultural acreage. An indigenous core, which was probably assembled from proximal, warmer, segments of Iberia, after the Younger Dryas, appears to have had sufficient numbers to found the Basques and assimilate subsequent newcomers. The original inhabitants included ancient Iberians and possibly some individuals with Neanderthal genes. Later additions have diluted the frequencies of the founders, but the new populace managed to retain a Basque identity.
The D Bebar [2012] study focused on haplogroup [Hg] H and sequenced the complete mtDNA genomes for many of the Hg H specimens, which were obtained from the seven Euskal Herria provinces and relevant, proximal populations. Participants older than sixty years were given preference to enhance the probability of deep ancestry. Hg H had a ca46% frequency among the Basques, [ibid].
A panel of 22 diagnostic coding region SNPs were typed and the entire control region was sequenced, which included HVS I and HVS II. The majority of the 908 samples belonged to HG H. Most of the remaining specimens have western Eurasian Hgs U5, J1, J2, V or T. The complete genomes of the 420 Hg H samples were sequenced. They were assigned to 129 sub-Hgs, with 59 singletons. Nine individuals could not be assigned to a known Hg and were designated as H*. Six dominant Hgs were identified that have an internal structure within Euskal Herria. They are in descending order of frequency H1j1 [12.4%], H1t1 [8.1%], H2a5a1 [5.2%], H1av1 [4.0%], H3c2a [3.3%] and H1e1a1 [2.9%]. These six Hgs are virtually absent in the reference set of more than 7000 complete mtDNA genomes of predominately western Eurasian origin and "could" be autochthonous to the region. The proportion of possible "autochthonous" Hgs varied appreciably between Basque and non-speaking Basque in adjacent territories. They account for 44-54% of the total Hg variation in Euskal Herria, which compares to 10-14% for proximal Spanish speakers. Time-depth estimates for the "autochthonous" Hgs range from 5.057- 3.187Ka, with separation times of 14.011-5.854Ka.This largely, but not completely, predates the arrival of Neolithic farmers. Contemporary Basques seem to exhibit continuity with their Mesolithic and possibly earlier ancestors [D Debar,2012].
This research revealed that a large sample of complete mtDNA genomes is required to ascertain the subtle levels ofpopulation stratification. It also attests to a degree of genetic isolation among the Basques. The same level of resolution will detect low frequency autochthonous Hgs in other European populations [eg: clade U5b3a1a characterizes Sardinians: D Bebar, 2012].
The above research has recorded the presence of ten Hg X1 individuals among the 908 samples. Previously Hg X1 had only been observed in the Near East and North Africa. Its presence in Iberia could infer the introduction of Hg X1 after the last glacial era or possibly after the Younger Dryas [?]. Hg X1 could have been dispersed from the Near East to the Franco-Cantabrian refugium? Alternately there is a remote possibility that it was introduced from North Africa? [speculation].
S Cardoso [2013] investigated the maternal ancestry of 548 autochthonous individuals from various Franco-Cantabriapopulations and sequenced 76 mitogenomes of the most representative lineages.This study identified the three mtDNA Hgs U5b1f, Jic5c1 and V22, which are representative of the these populations, especially the Basque. The Basque lands are deemed to have been in the epicentre of the Franco-Cantabria glacial refugium.The seclusion and diversity of these three female lineages support a local Franco-Cantabria origin during the Mesolithic era subsequent to the cold, dry Younger Dryas.Their signals of diversification and expansion broadly coincide with the termination of the cold, dry ca2200-1800BCE period [S Cardoso,2013].
Hg U5b1f represents more than 10% of the mtDNA variation, which has been detected in the Franco-Cantabrian samples.This lineage is primarily prevalent in SW France and adjacent northern Iberia.It has not been reported in Cantabria and peaks at about 17% in Navarre/Iparrade.Hgs J1c5c1 and V22 constitute about 1.7% and 2.3% respectively of the Franco-Cantabria maternal gene pool, with slightly higher frequencies of 2.0% and 2.6% estimated for the Basque.These three autochthonous, Mesolithic Hgs have contributed approximately an additional 15% to the Basque maternal gene pool, which elevates the total; Basque female component to about 35% [S Cardoso,2013].This is appreciably different from the male Y chromosome contribution.
A total of 835 specimens from 19 Euskal Herria and bordering locales were genotyped for the non-combining Y chromosome and yielded 35 Hgs. Except for four individuals, all the samples belonged to that branch of Hg R, which is defined by M 269 [R1b1b2], which is the most frequent in western Europe. The highly frequent R1b1b2b Hg's sub-clade R1b1b2b* [defined by P312] is the most common lineage in all populations bar one. The other most frequent sub-Hgs within R1b1b2-M269 were R1b1b25-L21, R1b1b2b3-STY2627 and R1b1b2b-M153.The presence of Hg I2a1-M26 has also been reported in other regions of Spain and has frequencies of 35-37% in Sardinia. It is very rare in other western European countries and is absent in Eastern Europe. E1b1bb-M81 has a low presence among the Basques and may represent a North African contribution to the gene pool [B Martinez-Cruz, 2012].
The higher degree of resolution of R1b1b2-M269 in this study revealed greater levels of Hg diversity, than had been detected in previous endeavours. Three Basques groups had lower levels than the others and the Basque generally had lower diversities than their immediate neighbours. STR variation within the common Hgs in the geographical study area infers that variation might date to the Neolithic. The current diversity in the region may also date to the Neolithic. The French Bretagne have Y chromosome affinities with the Basque speakers, while geographically closer French populationsdo not. The Bretagne people do not bear any cultural relationship to the Basque, even though there are genetic similarities. Demographic isolation may have created genetic heterogeneity among the Basque, when compared to non-Basquespeakers, in the Y chromosome, but not to the same extent in the mtDNA samples. Coalescence results indicate the existence of barriers to male gene flow in historical times, which seems to be consistent with the territories of the various pre-Roman Basque groups [ibid].
To define the origins and relationships of mtDNA Hg HV4, 53 samples were completely sequenced. The phylogeny of HV4 infers an Eastern European origin ca14.2Ka. The first split involved sub-clade HV4a. Its principal sub-Hgs are HV4a1 and HV4a2.The latter may have roots in the Near East ca 9.3Ka. The main HV4a1 sub-branch, Hv4a1a encompasses ca75% of the HV4 genomes and has a different geographic distribution, which is predominantly along the Cantabrian seaboard, with frequency peaks and its highest diversity in Euskal Herria and adjacent Cantabria lands. Phylogeny implies a coalescence age of ca5.4Ka. Its sub-clades Hv4a1a1, Hv4a1a2 and Hv4a1a3 evolved in this region ca4.4-1.9Ka.Only 76 control region mtDNA profiles were identified in the worldwide databases .About 46% occur in the Basque-Cantabria area and a significant proportion of the remainder in North America have Franco-Cantabria roots [Eg; French speaking Quebec, Canada]. There appears to have been a demographic episode of isolation in the Franco-Cantabria region ca5.4Ka.The existence of sub-clades implies genetic continuity [A Gomez-Carballa, 2012].
Hunter-gatherer and Neolithic specimens [49] from nine sites in Euskal Herria, Narvarre and Cantabria yielded eight mtDNA Hgs [H, U, K, J, HV, I, T and X] and 25 haplotypes.Hg H had a frequency of about 45%, which is broadly similar to the extant populations of the territory. Hg U [34.7%] was the second most common [eg; the Neolithic Navarre site of Los Cascajos 29.6%]. The Scandinavian, Central Europe and Cantabria hunter-gatherers are generally genetically similar. Only the Cantabria group largely resemble the present regional population. The hunter-gatherers in the Cantabria territory exhibit the least variation with the Neolithic specimens, which infers a greater degree of populace continuity in the Cantabria-Basque area. Hg j, a possible Neolithic marker, has only a 6.25% presence in Navarre, which is low by European standards. Hg V was not identified in any of the 49 specimens and has a minimal presence in the mtDNA studies of the Basque [M Hervilla,2012].
A Gonz'ales [2006] analysed 211 Basque samples utilizing the hypervariable segment of the mtDNA control region and diagnostic RFIP techniques.The four sequences, which were derived from haplogroup [hg] U8 were completely sequenced.Hg U was one of the earliest genetic lineages, that was dispersed from the Middle East to western Europe.Sub-hg U81a, which has a coalescence time of ca 13 +/-5.0Ka, has a 1.0% frequency in Basque lands.The greatest U8a diversity occurs on the Iberia Peninsula, which suggests that a few Basques could be descended from the Gravettians [ibid].The northern Iberian Basque provinces of Guipuzcoa and Viscaya have relatively high frequencies of hg U5.Subgroup U5b has its highest Iberian peak [15.4%] among the Guipuzcoas.U5b is rare among the Basque populations of France.Although hg U8a, which has a mean frequency of 1.3% among the Basques, has a scattered presence to the east in Catalonia, it has not been reported west of the Basque provinces.The high frequency variability of hg U5b and the wide differentiation of U8a among Basque lineages indicates that the Basques have maintained a low frequency of Palaeolithic maternal lineages in their extant female gene pool [O Garcia,2011].Analysis of mtDNA samples, which were collected from 55 males in the Arratia valley and the Goiherri region recorded an 18.2% frequency of hg U.The Adaieta cemetery samples contained four ancient U2e samples, which have not been identified among modern Basques.U2e is common in the Middle East [A Alzuaide,2007]. Analysis of the remains of a ca 8.5Ka old Basque fisherman from the cost of Hondarribia and Pessia suggests, that ca 50% of his diet was composed of marine food [A Arrizbalagg,2006].
Analysis of 623 Y chromosome samples identified 23 hgs.This study indicated, that the barrier between the Basques and their immediate neighbours was minimal.The Iberian populations had a reduced genetic structure and recent migrations have not totally erased the ancient Iberian Y chromosome patterns [C Flores,2004].A survey of eleven Alu insertion polymorphisms, which are DNA autosomal markers, did not detect appreciable allele frequency variations between the Basques and the adjacent Iberian populations.A genome scan of 650,000 SNPs, marginally differentiated the French Basques from other western Europeans.This study did not provide definitive evidence, that the Basques were a genetic outlier [P Garagnani,2009].Analysis of Alu elements by S Garcia-Obergon [2007] did not sustain a common genetic origin between Basques and north Africans or Caucasians. The Iberian Basques grouped with most European populations.The people in Guipuzcoa province, which is surrounded by other Basque provinces often appears to be the most differentiated Basque group.The population of Ireland has retained a higher indigenous component than the Basques, who were closer to the European migration routes.
The mtDNA genetic study by A Alzuaide [2006] provides information about temporal changes in the Basque female gene pool.The mtDNA of 65 human remains from the ca 550-770 ADE Basque Adaista cemetery were analysed and compared with a large selection of worldwide haplotypes and three prehistoric groups of proto-Basques[?] .The unique haplotypes 5,9 and 11 were not present in the Genbank samples or among the worldwide comparison sequences. Haplotypes 7,8,10,12,16 and 17 were deemed to be uncommon in Europe. The other six haplotypes were widely dispersed throughout western Europe.This distribution pattern has similarities to those populations on the Cantabrian fringe [ibid].
Two haplotypes of hg H account for 53% of the Aldaieta samples, which compares to 62.3% for extant Basques and 37-44% at the prehistoric sites of Rico Ramos, Langar and Sjapl, which range in age from the Neolithic to the Bronze Age .The percentage of hg H has increased since prehistoric times in Basques Lands.This differs from hg V, which has not been identified at the three prehistoric sites and is represented by a single sample at Aldaieta.The frequency of Hg V ranges from 3-20% among present day Basques.There were two hg K samples at Adaieta.Present day Basques have a 3.6% frequency of hg K.This represents a significant reduction since prehistoric times, when frequencies of hg K varied from 16.7-24.0%.Hg J is generally associated with the introduction of farming to Europe from the Fertile Cresent.At the three prehistoric sites hg J averaged 16.4%, which was reduced to 14.7% at Aldaieta.Extant Basques only have a 2.4% frequency of hg J.The frequency of hgs U5 and U2 have diminished from 16.7 among the prehistoric specimens to 13.7% among modern Basques.No hg W samples were identified among the prehistoric or historic samples, which contrasts with a 1.2% presence among the extant Basques.Hg I was not recorded in the prehistoric or the present day samples [ibid].Hg V has a 20% presence among modern Guipuzcoans [Torroni,1998].
The most variable region of the human genome is the noncoding displacement loop region, which is composed of about 1120 base pairs.The most polymorphic nucleotide positions within the control region are concentrated in HVS I and II.M Alfonso-Sanchez [2008] utilized both elements to focus on current Basques mtDNA distribution.Samples were collected from 55 males in the Arratia valley and Gaiherri region.When HVS I and II are combined 28 of the 35 mtDNA Basque lineages were unique. Comparisons with 14 European and north African populations indicated that the Basque specimens had the lowest level of variability among the female lineages in the study.The Black Death, influenza epidemics, etc., could have eliminated or reduced the numbers of some female lineages [eg;Hg J]. Y chromosome studies have revealed, that Basque paternal lineages exhibited low genetic diversity [ibid].
More than 95% of these Basque mtDNA specimens can be assigned to the European-specific hgs H, J, K, U, V and X, with H dominating 50.9%, U 18.2% and J 14.6%.Hg M, which has a low presence among northern Iberians was not identified in the Basque samples.Hg J has 9.0% frequency in Asturia,8.6% in Galacia and a ca 3.0% average across the Basque Lands.Sub-hgs J1a1 [10.9%] and J2a [3.6%] have "relatively" high presences.Hg J was not reported in the comparative Caucasus samples.The French Basques have appreciably higher frequencies of hg J than their Iberian counterparts.Galacia has a very low hg U frequency, while Saragossa has a significantly higher Hg T content.No African or U8a lineages were identified among these Basque individuals.Hg V was poorly represented, when compared to earlier studies. There are considerable variations in the mtDNA lineage frequencies in different Basque regions, and there is a paucity of prehistorical genetuic data that can be used to make direct comparisons between prehistoric and present day mtDNA hg frequencies and distribution patterns in specific areas [ibid].The pre- and historical Basques received external gene flow, which is not always reflected to the same extent in extant Basques populations.S Alonsel [2006] contends that they may not always have been the focus of major population expansions and might not be best representatives of the ancient European gene pool.It appears that hg V was introduced to the Basques at a relatively late date.There are genetic discontinuities between prehistoric/historic Basques and the extant populations [A Alzuaide,2006].
O Gracia et al [2011] sequenced the HVS I and II components for 413 European mtDNA samples and integrated the new data with 5436 specimens from the available literature.The 2011 study revealed.that 236 of the 413 individuals harboured hg H [19 subgroups].A total of 295 different haplotypes were identified.The proportion of different haplotypes was lower [64%] among the Basques than it was in other northern Iberian populations [90%].The Basques appear to have been less susceptible to external influences.However, the north African clades M1 and M6 were recorded in the Basque samples.The 13.5% presence of hg T in Viscaya contrasts with the 4.0% in Guipuzcoa and Alva, which emphasizes the variations in mtDNA distribution between the different regions of Euskal Herra and the adjacent Iberian provinces [ibid].The mtDNA hg dispersement patterns among the French Basques varies from their Iberian counterparts [eg;hg J:Richard,2007].
The frequencies of mtDNa hg V are significantly higher in southern Iberia than in the extreme far north of Spain.The presence of hg V in Euskal Herra ranges from 11.7% in Guipuzcoa to 5.9% in Alva.There is no diagnostic evidence that hg V expanded northward from a Basque refugium after the last glacial era.Although the highest frequency of mtDNA hg H has been recorded in northern most Iberia, diversity values are considerably higher in NE Iberia.However, overall H1 has a greater diversity in the Near East than in Iberia.The rare subgroup H1t appears to be restricted to the Iberian peninsula, where H3 is most abundant, but not the most diverse [O Garcia,2011].
C Capelli [2003] reported that the Basques Y chromosome hgs tend to cluster with those of Ireland [Castlerea], Cornwall, and western Wales [eg:Haveford West, Llangfini], which can be attributed to the northward expansion of Iberians from NW coastal communities in Spain after the Younger Dryas [ca 9700 BCE].The close genetic link between the Basques and Castlerea, Ireland, infers minimal "retained admixture" from the expansion of Neolithic male agriculturalists [ibid].
S Oppenheimer [2006] used Y chromosome SRR markers to reconstruct ancient population movements.Hg R was probably introduced to central Europe by the Gravettians from the Eastern Russian plains ca 30Ka ago.Today hg R1b and its 16 descendant lineages have an 86% frequency among the Basques.Some of these lineages expanded north from Iberia refugia after the Younger Dryas.The Y chromosome I1b2 followed a northern Mediterranean coastal route to the west.It contributed 41% to the present day Sardinian male gene pool, but only 6% to the Basques, who should have easily assimilated a relatively low percentage of newcomers.There has been a lower exchange of Y chromosomes between the western Basques and their neighbours, when compared to the degree of admixture to the east, where Basques and Aragon share the Ebro valley [M Iriande, 2003].Basque females were less restricted in their choice of partners [M Brian,2004].Galician G, M, and KM immunoglobian allotype allele frequencies indicate significantly large statistical variations between the Galicians and the Basques.The Guipuzean Basques are the most distinct [R Calderon,2007].
HLA hgs DR3-DQ2.5 and DR7-DO22 are common among the Basques and some west African populations.A29-Cw16-B44 occurs in west Africa, with a peak frequency among the Basques and a peak diversity in the Pasiegas valley.There appears to have been a time lag between the arrival of this genetic lineage in Iberia and its northward expansion, which could infer a slow dispersal through Iberia from north Africa prior to the Moor era.It has an appreciable component in the Pasiegas valley, which could be the site of recombination.This distinct feature suggests ancient admixture. There is A29-Cw16 disequilibrium among the Irish [P Deitiker,2009].
Collation of the available genetic data suggest, that the distant ancestors of the present day Euskal Herria people became established immediately after the end of the Younger Dryas ca 9700 BCE or earlier. However, subsequent influxes of newcomers over the interim have diluted and changed the original gene pool.Cantabria has closer affinities to the proximal Vizcayan Basque people than to the inhabitants of the other Basque provinces.Most mtDNA studies suggest that the modern Iberians share a common genetic background with other Europeans, but are distinct from Europeans.In the Basque Lands this distinction is even more apparent, because the Basques tended to evolve in discrete genetic clusters, with restricted local expansions. The Basques identity is essentially determined by their unique language. Future genetic studies may contribute to resolving some of the Basques enigmas.
was probably spoken during historical times. Euskal Herria "might" have at one time extended from the Garonne River in the north to the Erbo River in the south [equivocal]. Basque language inscriptions and speech remnants have been identified outside of historical Euskal Herria [Gorrochategui,1995]. The theonyms, some place and personal names suggest that the ancient residents of Aquitania could have conversed in a proto-Basque tongue [B Martinez-Cruz,2012].
The Basque inhabit rugose terrain in the SW extremity of France and adjacent Spain, which is composed of seven provinces. During the last glacial era the polar front reached the Pyrenees and temperatures are estimated to have been about 15 degrees C below today's average levels. The unfavourable climatic conditions probably fragmented northern Iberian populations and limited gene flow between these groups, which subsequently could have been partially perpetuated by the rugged topography over a portion of the Basque Lands.This premise is compatible with the eight distinct regional Euskera dialects, that are spoken by the Basques [de Yrizar].These lands are called Euskal Herria, the landof the Euskera speakers. It is their unique, ancient, non-Indo-European, agglutinating language, which identifies the Basques, who have a high frequency of Rh negative blood [ca 25%].No linguistic equivalent to their language has been found. The origin of this tongue is unknown. A proto-type "might" have been introduced to the Basque lands by people, who predated the influx of Neolithic agriculturalists, who "may" have spoken an Indo-European language [speculation].
Preservation of the Basque identity contrasts sharply with the physical, but not genetic, disappearance of the Neanderthals. The sparse scatterings of small Neanderthal groups were not able to cope with the appreciable influxes of Homo sapiens. The Basques were largely concentrated in a relatively rugged region and large tracts of their land were not prime agricultural acreage. An indigenous core, which was probably assembled from proximal, warmer, segments of Iberia, after the Younger Dryas, appears to have had sufficient numbers to found the Basques and assimilate subsequent newcomers. The original inhabitants included ancient Iberians and possibly some individuals with Neanderthal genes. Later additions have diluted the frequencies of the founders, but the new populace managed to retain a Basque identity.
The D Bebar [2012] study focused on haplogroup [Hg] H and sequenced the complete mtDNA genomes for many of the Hg H specimens, which were obtained from the seven Euskal Herria provinces and relevant, proximal populations. Participants older than sixty years were given preference to enhance the probability of deep ancestry. Hg H had a ca46% frequency among the Basques, [ibid].
A panel of 22 diagnostic coding region SNPs were typed and the entire control region was sequenced, which included HVS I and HVS II. The majority of the 908 samples belonged to HG H. Most of the remaining specimens have western Eurasian Hgs U5, J1, J2, V or T. The complete genomes of the 420 Hg H samples were sequenced. They were assigned to 129 sub-Hgs, with 59 singletons. Nine individuals could not be assigned to a known Hg and were designated as H*. Six dominant Hgs were identified that have an internal structure within Euskal Herria. They are in descending order of frequency H1j1 [12.4%], H1t1 [8.1%], H2a5a1 [5.2%], H1av1 [4.0%], H3c2a [3.3%] and H1e1a1 [2.9%]. These six Hgs are virtually absent in the reference set of more than 7000 complete mtDNA genomes of predominately western Eurasian origin and "could" be autochthonous to the region. The proportion of possible "autochthonous" Hgs varied appreciably between Basque and non-speaking Basque in adjacent territories. They account for 44-54% of the total Hg variation in Euskal Herria, which compares to 10-14% for proximal Spanish speakers. Time-depth estimates for the "autochthonous" Hgs range from 5.057- 3.187Ka, with separation times of 14.011-5.854Ka.This largely, but not completely, predates the arrival of Neolithic farmers. Contemporary Basques seem to exhibit continuity with their Mesolithic and possibly earlier ancestors [D Debar,2012].
This research revealed that a large sample of complete mtDNA genomes is required to ascertain the subtle levels ofpopulation stratification. It also attests to a degree of genetic isolation among the Basques. The same level of resolution will detect low frequency autochthonous Hgs in other European populations [eg: clade U5b3a1a characterizes Sardinians: D Bebar, 2012].
The above research has recorded the presence of ten Hg X1 individuals among the 908 samples. Previously Hg X1 had only been observed in the Near East and North Africa. Its presence in Iberia could infer the introduction of Hg X1 after the last glacial era or possibly after the Younger Dryas [?]. Hg X1 could have been dispersed from the Near East to the Franco-Cantabrian refugium? Alternately there is a remote possibility that it was introduced from North Africa? [speculation].
S Cardoso [2013] investigated the maternal ancestry of 548 autochthonous individuals from various Franco-Cantabriapopulations and sequenced 76 mitogenomes of the most representative lineages.This study identified the three mtDNA Hgs U5b1f, Jic5c1 and V22, which are representative of the these populations, especially the Basque. The Basque lands are deemed to have been in the epicentre of the Franco-Cantabria glacial refugium.The seclusion and diversity of these three female lineages support a local Franco-Cantabria origin during the Mesolithic era subsequent to the cold, dry Younger Dryas.Their signals of diversification and expansion broadly coincide with the termination of the cold, dry ca2200-1800BCE period [S Cardoso,2013].
Hg U5b1f represents more than 10% of the mtDNA variation, which has been detected in the Franco-Cantabrian samples.This lineage is primarily prevalent in SW France and adjacent northern Iberia.It has not been reported in Cantabria and peaks at about 17% in Navarre/Iparrade.Hgs J1c5c1 and V22 constitute about 1.7% and 2.3% respectively of the Franco-Cantabria maternal gene pool, with slightly higher frequencies of 2.0% and 2.6% estimated for the Basque.These three autochthonous, Mesolithic Hgs have contributed approximately an additional 15% to the Basque maternal gene pool, which elevates the total; Basque female component to about 35% [S Cardoso,2013].This is appreciably different from the male Y chromosome contribution.
A total of 835 specimens from 19 Euskal Herria and bordering locales were genotyped for the non-combining Y chromosome and yielded 35 Hgs. Except for four individuals, all the samples belonged to that branch of Hg R, which is defined by M 269 [R1b1b2], which is the most frequent in western Europe. The highly frequent R1b1b2b Hg's sub-clade R1b1b2b* [defined by P312] is the most common lineage in all populations bar one. The other most frequent sub-Hgs within R1b1b2-M269 were R1b1b25-L21, R1b1b2b3-STY2627 and R1b1b2b-M153.The presence of Hg I2a1-M26 has also been reported in other regions of Spain and has frequencies of 35-37% in Sardinia. It is very rare in other western European countries and is absent in Eastern Europe. E1b1bb-M81 has a low presence among the Basques and may represent a North African contribution to the gene pool [B Martinez-Cruz, 2012].
The higher degree of resolution of R1b1b2-M269 in this study revealed greater levels of Hg diversity, than had been detected in previous endeavours. Three Basques groups had lower levels than the others and the Basque generally had lower diversities than their immediate neighbours. STR variation within the common Hgs in the geographical study area infers that variation might date to the Neolithic. The current diversity in the region may also date to the Neolithic. The French Bretagne have Y chromosome affinities with the Basque speakers, while geographically closer French populationsdo not. The Bretagne people do not bear any cultural relationship to the Basque, even though there are genetic similarities. Demographic isolation may have created genetic heterogeneity among the Basque, when compared to non-Basquespeakers, in the Y chromosome, but not to the same extent in the mtDNA samples. Coalescence results indicate the existence of barriers to male gene flow in historical times, which seems to be consistent with the territories of the various pre-Roman Basque groups [ibid].
To define the origins and relationships of mtDNA Hg HV4, 53 samples were completely sequenced. The phylogeny of HV4 infers an Eastern European origin ca14.2Ka. The first split involved sub-clade HV4a. Its principal sub-Hgs are HV4a1 and HV4a2.The latter may have roots in the Near East ca 9.3Ka. The main HV4a1 sub-branch, Hv4a1a encompasses ca75% of the HV4 genomes and has a different geographic distribution, which is predominantly along the Cantabrian seaboard, with frequency peaks and its highest diversity in Euskal Herria and adjacent Cantabria lands. Phylogeny implies a coalescence age of ca5.4Ka. Its sub-clades Hv4a1a1, Hv4a1a2 and Hv4a1a3 evolved in this region ca4.4-1.9Ka.Only 76 control region mtDNA profiles were identified in the worldwide databases .About 46% occur in the Basque-Cantabria area and a significant proportion of the remainder in North America have Franco-Cantabria roots [Eg; French speaking Quebec, Canada]. There appears to have been a demographic episode of isolation in the Franco-Cantabria region ca5.4Ka.The existence of sub-clades implies genetic continuity [A Gomez-Carballa, 2012].
Hunter-gatherer and Neolithic specimens [49] from nine sites in Euskal Herria, Narvarre and Cantabria yielded eight mtDNA Hgs [H, U, K, J, HV, I, T and X] and 25 haplotypes.Hg H had a frequency of about 45%, which is broadly similar to the extant populations of the territory. Hg U [34.7%] was the second most common [eg; the Neolithic Navarre site of Los Cascajos 29.6%]. The Scandinavian, Central Europe and Cantabria hunter-gatherers are generally genetically similar. Only the Cantabria group largely resemble the present regional population. The hunter-gatherers in the Cantabria territory exhibit the least variation with the Neolithic specimens, which infers a greater degree of populace continuity in the Cantabria-Basque area. Hg j, a possible Neolithic marker, has only a 6.25% presence in Navarre, which is low by European standards. Hg V was not identified in any of the 49 specimens and has a minimal presence in the mtDNA studies of the Basque [M Hervilla,2012].
A Gonz'ales [2006] analysed 211 Basque samples utilizing the hypervariable segment of the mtDNA control region and diagnostic RFIP techniques.The four sequences, which were derived from haplogroup [hg] U8 were completely sequenced.Hg U was one of the earliest genetic lineages, that was dispersed from the Middle East to western Europe.Sub-hg U81a, which has a coalescence time of ca 13 +/-5.0Ka, has a 1.0% frequency in Basque lands.The greatest U8a diversity occurs on the Iberia Peninsula, which suggests that a few Basques could be descended from the Gravettians [ibid].The northern Iberian Basque provinces of Guipuzcoa and Viscaya have relatively high frequencies of hg U5.Subgroup U5b has its highest Iberian peak [15.4%] among the Guipuzcoas.U5b is rare among the Basque populations of France.Although hg U8a, which has a mean frequency of 1.3% among the Basques, has a scattered presence to the east in Catalonia, it has not been reported west of the Basque provinces.The high frequency variability of hg U5b and the wide differentiation of U8a among Basque lineages indicates that the Basques have maintained a low frequency of Palaeolithic maternal lineages in their extant female gene pool [O Garcia,2011].Analysis of mtDNA samples, which were collected from 55 males in the Arratia valley and the Goiherri region recorded an 18.2% frequency of hg U.The Adaieta cemetery samples contained four ancient U2e samples, which have not been identified among modern Basques.U2e is common in the Middle East [A Alzuaide,2007]. Analysis of the remains of a ca 8.5Ka old Basque fisherman from the cost of Hondarribia and Pessia suggests, that ca 50% of his diet was composed of marine food [A Arrizbalagg,2006].
Analysis of 623 Y chromosome samples identified 23 hgs.This study indicated, that the barrier between the Basques and their immediate neighbours was minimal.The Iberian populations had a reduced genetic structure and recent migrations have not totally erased the ancient Iberian Y chromosome patterns [C Flores,2004].A survey of eleven Alu insertion polymorphisms, which are DNA autosomal markers, did not detect appreciable allele frequency variations between the Basques and the adjacent Iberian populations.A genome scan of 650,000 SNPs, marginally differentiated the French Basques from other western Europeans.This study did not provide definitive evidence, that the Basques were a genetic outlier [P Garagnani,2009].Analysis of Alu elements by S Garcia-Obergon [2007] did not sustain a common genetic origin between Basques and north Africans or Caucasians. The Iberian Basques grouped with most European populations.The people in Guipuzcoa province, which is surrounded by other Basque provinces often appears to be the most differentiated Basque group.The population of Ireland has retained a higher indigenous component than the Basques, who were closer to the European migration routes.
The mtDNA genetic study by A Alzuaide [2006] provides information about temporal changes in the Basque female gene pool.The mtDNA of 65 human remains from the ca 550-770 ADE Basque Adaista cemetery were analysed and compared with a large selection of worldwide haplotypes and three prehistoric groups of proto-Basques[?] .The unique haplotypes 5,9 and 11 were not present in the Genbank samples or among the worldwide comparison sequences. Haplotypes 7,8,10,12,16 and 17 were deemed to be uncommon in Europe. The other six haplotypes were widely dispersed throughout western Europe.This distribution pattern has similarities to those populations on the Cantabrian fringe [ibid].
Two haplotypes of hg H account for 53% of the Aldaieta samples, which compares to 62.3% for extant Basques and 37-44% at the prehistoric sites of Rico Ramos, Langar and Sjapl, which range in age from the Neolithic to the Bronze Age .The percentage of hg H has increased since prehistoric times in Basques Lands.This differs from hg V, which has not been identified at the three prehistoric sites and is represented by a single sample at Aldaieta.The frequency of Hg V ranges from 3-20% among present day Basques.There were two hg K samples at Adaieta.Present day Basques have a 3.6% frequency of hg K.This represents a significant reduction since prehistoric times, when frequencies of hg K varied from 16.7-24.0%.Hg J is generally associated with the introduction of farming to Europe from the Fertile Cresent.At the three prehistoric sites hg J averaged 16.4%, which was reduced to 14.7% at Aldaieta.Extant Basques only have a 2.4% frequency of hg J.The frequency of hgs U5 and U2 have diminished from 16.7 among the prehistoric specimens to 13.7% among modern Basques.No hg W samples were identified among the prehistoric or historic samples, which contrasts with a 1.2% presence among the extant Basques.Hg I was not recorded in the prehistoric or the present day samples [ibid].Hg V has a 20% presence among modern Guipuzcoans [Torroni,1998].
The most variable region of the human genome is the noncoding displacement loop region, which is composed of about 1120 base pairs.The most polymorphic nucleotide positions within the control region are concentrated in HVS I and II.M Alfonso-Sanchez [2008] utilized both elements to focus on current Basques mtDNA distribution.Samples were collected from 55 males in the Arratia valley and Gaiherri region.When HVS I and II are combined 28 of the 35 mtDNA Basque lineages were unique. Comparisons with 14 European and north African populations indicated that the Basque specimens had the lowest level of variability among the female lineages in the study.The Black Death, influenza epidemics, etc., could have eliminated or reduced the numbers of some female lineages [eg;Hg J]. Y chromosome studies have revealed, that Basque paternal lineages exhibited low genetic diversity [ibid].
More than 95% of these Basque mtDNA specimens can be assigned to the European-specific hgs H, J, K, U, V and X, with H dominating 50.9%, U 18.2% and J 14.6%.Hg M, which has a low presence among northern Iberians was not identified in the Basque samples.Hg J has 9.0% frequency in Asturia,8.6% in Galacia and a ca 3.0% average across the Basque Lands.Sub-hgs J1a1 [10.9%] and J2a [3.6%] have "relatively" high presences.Hg J was not reported in the comparative Caucasus samples.The French Basques have appreciably higher frequencies of hg J than their Iberian counterparts.Galacia has a very low hg U frequency, while Saragossa has a significantly higher Hg T content.No African or U8a lineages were identified among these Basque individuals.Hg V was poorly represented, when compared to earlier studies. There are considerable variations in the mtDNA lineage frequencies in different Basque regions, and there is a paucity of prehistorical genetuic data that can be used to make direct comparisons between prehistoric and present day mtDNA hg frequencies and distribution patterns in specific areas [ibid].The pre- and historical Basques received external gene flow, which is not always reflected to the same extent in extant Basques populations.S Alonsel [2006] contends that they may not always have been the focus of major population expansions and might not be best representatives of the ancient European gene pool.It appears that hg V was introduced to the Basques at a relatively late date.There are genetic discontinuities between prehistoric/historic Basques and the extant populations [A Alzuaide,2006].
O Gracia et al [2011] sequenced the HVS I and II components for 413 European mtDNA samples and integrated the new data with 5436 specimens from the available literature.The 2011 study revealed.that 236 of the 413 individuals harboured hg H [19 subgroups].A total of 295 different haplotypes were identified.The proportion of different haplotypes was lower [64%] among the Basques than it was in other northern Iberian populations [90%].The Basques appear to have been less susceptible to external influences.However, the north African clades M1 and M6 were recorded in the Basque samples.The 13.5% presence of hg T in Viscaya contrasts with the 4.0% in Guipuzcoa and Alva, which emphasizes the variations in mtDNA distribution between the different regions of Euskal Herra and the adjacent Iberian provinces [ibid].The mtDNA hg dispersement patterns among the French Basques varies from their Iberian counterparts [eg;hg J:Richard,2007].
The frequencies of mtDNa hg V are significantly higher in southern Iberia than in the extreme far north of Spain.The presence of hg V in Euskal Herra ranges from 11.7% in Guipuzcoa to 5.9% in Alva.There is no diagnostic evidence that hg V expanded northward from a Basque refugium after the last glacial era.Although the highest frequency of mtDNA hg H has been recorded in northern most Iberia, diversity values are considerably higher in NE Iberia.However, overall H1 has a greater diversity in the Near East than in Iberia.The rare subgroup H1t appears to be restricted to the Iberian peninsula, where H3 is most abundant, but not the most diverse [O Garcia,2011].
C Capelli [2003] reported that the Basques Y chromosome hgs tend to cluster with those of Ireland [Castlerea], Cornwall, and western Wales [eg:Haveford West, Llangfini], which can be attributed to the northward expansion of Iberians from NW coastal communities in Spain after the Younger Dryas [ca 9700 BCE].The close genetic link between the Basques and Castlerea, Ireland, infers minimal "retained admixture" from the expansion of Neolithic male agriculturalists [ibid].
S Oppenheimer [2006] used Y chromosome SRR markers to reconstruct ancient population movements.Hg R was probably introduced to central Europe by the Gravettians from the Eastern Russian plains ca 30Ka ago.Today hg R1b and its 16 descendant lineages have an 86% frequency among the Basques.Some of these lineages expanded north from Iberia refugia after the Younger Dryas.The Y chromosome I1b2 followed a northern Mediterranean coastal route to the west.It contributed 41% to the present day Sardinian male gene pool, but only 6% to the Basques, who should have easily assimilated a relatively low percentage of newcomers.There has been a lower exchange of Y chromosomes between the western Basques and their neighbours, when compared to the degree of admixture to the east, where Basques and Aragon share the Ebro valley [M Iriande, 2003].Basque females were less restricted in their choice of partners [M Brian,2004].Galician G, M, and KM immunoglobian allotype allele frequencies indicate significantly large statistical variations between the Galicians and the Basques.The Guipuzean Basques are the most distinct [R Calderon,2007].
HLA hgs DR3-DQ2.5 and DR7-DO22 are common among the Basques and some west African populations.A29-Cw16-B44 occurs in west Africa, with a peak frequency among the Basques and a peak diversity in the Pasiegas valley.There appears to have been a time lag between the arrival of this genetic lineage in Iberia and its northward expansion, which could infer a slow dispersal through Iberia from north Africa prior to the Moor era.It has an appreciable component in the Pasiegas valley, which could be the site of recombination.This distinct feature suggests ancient admixture. There is A29-Cw16 disequilibrium among the Irish [P Deitiker,2009].
Collation of the available genetic data suggest, that the distant ancestors of the present day Euskal Herria people became established immediately after the end of the Younger Dryas ca 9700 BCE or earlier. However, subsequent influxes of newcomers over the interim have diluted and changed the original gene pool.Cantabria has closer affinities to the proximal Vizcayan Basque people than to the inhabitants of the other Basque provinces.Most mtDNA studies suggest that the modern Iberians share a common genetic background with other Europeans, but are distinct from Europeans.In the Basque Lands this distinction is even more apparent, because the Basques tended to evolve in discrete genetic clusters, with restricted local expansions. The Basques identity is essentially determined by their unique language. Future genetic studies may contribute to resolving some of the Basques enigmas.
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