U6 spread from Northern Morocco, probably in two waves: the oldest one (U6a) related to the spread of Oranian culture (since c. 20 Ka BP) and the more recent one (U6b'd and U6c) in the context of the Early Holocene climatic amelioration.
U6 is most common in Canary Islands (~18%), NW Africa (5-9%), as well as Portugal, Ethiopia and Cape Verde (~3%).
U6a is the most common subclade. It is divided as follows:
- U6a1: a mostly European clade, which expanded since the Solutrean.
- U6a2'8: widely distributed in North Africa, Europe and Ethiopia especially. U6a2 is believed to have expanded also c. 20 Ka ago.
- U6a3: also widely distributed with many subclades in West Africa.
- U6a4: Italy, Iraq.
- U6a5: Italy, NW Africa, Central Africa.
- U6a6: NW Africa only.
- U6a7: NW Africa and also some in Europe. U6a7a1 is a French clade with a colonial founder effect in Canada.
U6b, like U6a3, shows some distribution towards West Africa but also many other areas. U6b5 is an Arab-specific subclade.
U6d is found mostly in NW Africa but also Iberia, Ethiopia and some other parts of Europe.
U6c is smaller than its relatives. Typical of NW Africa it is also found occasionally in Europe (France, Italy, Andalusia).