The haplotype of the mitochondrial DNA known as U5 entered in Europe during the Upper Paleolithic and developed varieties as the U8a, native of the Basque Country, which is considered to be Prehistoric, and as the J group, which is also frequent in the Basque population. The works of Alzualde A, Izagirre N, Alonso S, Alonso A, de la Rua C. about mitochondrial DNA of the Human remains found in the Prehistoric graveyard of Alaieta, in Alava, note that there are no differences between these remains and others found across Atlantic Europe. Studies based on the Y chromosome genetically relate the Basques with the Celtic Welsh, and Irish; Stephen Oppenheimer from the University of Oxford says that the current inhabitants of the British Isles have their origin in the Basque refuge during the last Ice age. Oppenheimer reached this conclusion through the study of correspondences in the frequencies of genetic markers between various European regions.Los británicos descienden de los vascos de la Edad de Hielo. elcorreodigital.comGenes link Celts to Basques "On the Y-chromosome, the Celtic populations turn out to be statistically indistinguishable from the Basques," Professor Goldstein said. The haplogroup R1b, can be found most frequently in the Basque Country (91%), Wales (89%) and Ireland (81%). The age of subclade which Basque carry, Haplogroup 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. In 2015, a new scientific study of Basque DNA was published which seems to indicate that Basques are descendants of Neolithic farmers who mixed with local hunters before 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 official findings were published in Proceedings of the National Academy of Sciences of the United States of America. "Our results show that the Basques trace their ancestry to early farming