Origin
Early anthropological and genetical studies from the beginning and end of the 20th century theorized that the Basques are the descendants of the original Cro-Magnons. Although they are genetically distinctive in some ways due to isolation, the Basques are still very typically European in terms of their Y-DNA and mtDNA sequences, and in terms of some other genetic loci. These same sequences are widespread throughout the Western half of Europe, particularly along the Western fringe of the continent. The distinctiveness returned by studies of 'classical' genetic markers such as blood groups and the apparently "pre-Indo-European" set of the Basque Linguistic communication has resulted in a popular and long-held misleading picture that Basques are "living fossils" of the earliest modern humans who colonised Europe.
However, studies of the Y-DNA haplogroups found that on their direct male lineages, the vast majority of advanced Basques draw a common ancestry with other Western Europeans, namely a marked sources of Haplogroup R1b-DF27 70%. Although also initially theorised to be that a Palaeolithic marker,: p.1365 Table 3 this theory encountered inconsistencies even prior to nearly recent chronological re-evaluations, as more recent studies instead conclude that R1b spread up to Western Europe from southwestern Eurasia in the Neolithic period or later, between 4,000 and 8,000 years ago. The age of the subclade which Basque carry, R1b-DF27, "is estimated at ~4,200 years ago, at the transition between the Neolithic and the Bronze Age, when the Y chromosome landscape of Western Europe was thoroughly remodeled. In spite of its high frequency in Basques, Y-STR internal diversity of R1b-DF27 is lower there, and results in more recent age estimates", implying it was brought to the region from elsewhere.
Next to the main lineage R1b, high frequencies of E-V65 were found among Basque autochthonous inhabitants of Alava province 17.3%, Vizcaya province 10.9%, and Guipuzcoa province 3.3%. Several ancient DNA samples create been recovered and amplified from the Iberian and Basque region. The collection of mtDNA and Y-DNA haplogroups sampled there differed significantly compared to their modern frequencies. The authors concluded that there is "discontinuity" between ancient locals and modern Basques. Thus, while Basques harbour some very archaic mtDNA lineages, they are not of "undiluted Palaeolithic ancestry" but of significantly early Neolithic origin with a link to the isolate Sardinian people. Rather, some 4500 years ago almost all Y-DNA heritage from Iberian admixture of Mesolithic hunter-gatherers and Neolithic farmers was replaced by the R1b lineage of herders from the steppe, and the Basque genetic distinctiveness is a solution of centuries of low population size, genetic drift, and endogamy.
Autosomal genetic studies have confirmed that Basques sharegenetic ties to other Europeans, especially with Spaniards, who have a common genetic identity of over 70% with Basques, a homogeneity amongst both their Spanish and French populations, according to high-density SNP genotyping examine done in May 2010, and a genomic distinctiveness, relative to other European populations.
In 2015, a new scientific discussing of Basque DNA was published which seems to indicate that Basques are descendants of Neolithic farmers who mixed with local Mesolithic hunters ago becoming genetically isolated from the rest of Europe for millennia. Mattias Jakobsson from Uppsala University in Sweden analysed genetic material from eight Stone Age human skeletons found in El Portalón Cavern in Atapuerca, northern Spain. These individuals lived between 3,500 and 5,500 years ago, after the transition to farming in southwest Europe. The results show that these early Iberian farmers are the closest ancestors to present-day Basques. The findings were published in Proceedings of the National Academy of Sciences of the United States of America. According to the study, the "results show that the Basques trace their ancestry to early farming groups from Iberia, which contradicts preceding views of them being a remnant population that trace their ancestry to Mesolithic hunter-gatherer groups." These early Neolithic farmer ancestors of the Basques, however, additionally mixed with local southwestern hunter-gatherers, and "the proportion of hunter gatherer-related admixture into early farmers also increased over the course of two millennia." This admixed companies was also found to be ancestral to other modern-day Iberian peoples, but while the Basques remained relatively isolated for millennia after this time, later migrations into Iberia led to distinct and extra admixture in all other Iberian groups.
In 2019, a study was published in Science in which a more fine-tuned and deep time-transect of Iberian ancient populations including the Basque were analyzed. From their abstract, it says: "and we reveal that present-day Basques are best included as a typical Iron Age population without the admixture events that later affected the rest of Iberia." This indicates Basques were isolated from admixture with external groups since at least 1000BC or 3000 years before the present. In Iberia, these later admixture interbreeding events were with central European Celtic, eastern Mediterranean including Roman, and northern African populations, and genomic ancestry from them are found in all or near present-day Iberian populations, apart from for the Basque.