Haplogroup U

Haplogroup U is a human mitochondrial DNA haplogroup (mtDNA). The clade arose from haplogroup R, likely during the early Upper Paleolithic. Its various subclades (labelled U1–U9, diverging over the course of the Upper Paleolithic) are found widely distributed across Northern and Eastern Europe, Central, Western and South Asia, as well as North Africa, the Horn of Africa, and the Canary Islands.Subgroup U6a reflects the first African expansion from the Maghreb returning to the east. Derivative clade U6a1 signals a posterior movement from East Africa back to the Maghreb and the Near East. This migration coincides with the probable Afroasiatic linguistic expansion. U6b and U6c clades, restricted to West Africa, had more localized expansions. U6b probably reached the Iberian Peninsula during the Capsian diffusion in North Africa. Two autochthonous derivatives of these clades (U6b1 and U6c1) indicate the arrival of North African settlers to the Canarian Archipelago in prehistoric times, most probably due to the Saharan desiccation. The absence of these Canarian lineages nowadays in Africa suggests important demographic movements in the western area of this Continent.Phylogenetic tree of human mitochondrial DNA (mtDNA) haplogroups Haplogroup U is a human mitochondrial DNA haplogroup (mtDNA). The clade arose from haplogroup R, likely during the early Upper Paleolithic. Its various subclades (labelled U1–U9, diverging over the course of the Upper Paleolithic) are found widely distributed across Northern and Eastern Europe, Central, Western and South Asia, as well as North Africa, the Horn of Africa, and the Canary Islands. The haplogroup U8b's most common subclade is haplogroup K, which is estimated to date to between 30,000 and 22,000 years ago. Haplogroup U descends from the haplogroup R mtDNA branch of the phylogenetic tree. The defining mutations (A11467G, A12308G, G12372A) are estimated to have arisen between 43,000 and 50,000 years ago, in the early Upper Paleolithic (around 46,530 ± 3,290 years before present, with a 95% confidence interval per Behar et al., 2012). Ancient DNA classified as belonging to the U* mitochondrial haplogroup has been recovered from human skeletal remains found in Western Siberia, which have been dated to c. 45,000 years ago. The mitogenome (33-fold coverage) of the Peştera Muierii 1 individual (PM1) from Romania (35 ky cal BP) has been identified as the basal haplogroup U6* not previously found in any ancient or present-day humans. Haplogroup U has been found among Iberomaurusian specimens dating from the Epipaleolithic at the Taforalt and Afalou prehistoric sites. Among the Taforalt individuals, around 13% of the observed haplotypes belonged to various U subclades, including U4a2b (1/24; 4%), U4c1 (1/24; 4%), and U6d3 (1/24; 4%). A further 41% of the analysed haplotypes could be assigned to either haplogroup U or haplogroup H. Among the Afalou individuals, 44% of the analysed haplotypes could be assigned to either haplogroup U or haplogroup H (3/9; 33%). Haplogroup U has also been observed among ancient Egyptian mummies excavated at the Abusir el-Meleq archaeological site in Middle Egypt, dated to the 1st millennium BC. Additionally, haplogroup U has been observed in ancient Guanche fossils excavated in Gran Canaria and Tenerife on the Canary Islands, which have been radiocarbon-dated to between the 7th and 11th centuries CE. All of the clade-bearing individuals were inhumed at the Tenerife site, with these specimens found to belong to the U6b1a (4/7; 57%) and U6b (1/7; 14%) subclades. Haplogroup U is found in 15% of Indian caste and 8% of Indian tribal populations.Haplogroup U is found in approximately 11% of native Europeans and is held as the oldest maternal haplogroup found in that region. In a 2013 study, all but one of the ancient modern human sequences from Europe belonged to maternal haplogroup U, thus confirming previous findings that haplogroup U was the dominant type of Mitochondrial DNA (mtDNA) in Europe before the spread of agriculture into Europe and the presence and the spread of the Indo-Europeans in Western Europe. Haplogroup U has various subclades numbered U1 to U9. Haplogroup K is a subclade of U8. The old age has led to a wide distribution of the descendant subgroups across Western Eurasia, North Africa, and South Asia. Some subclades of haplogroup U have a more specific geographic range.