I believe these brother clades to R-U152 and R-L21 include the
Basque/Iberian migration to the British Isles. R-U152 is noted in
Spain @
http://freepages.genealogy.rootsweb.ancestry.com/~nolenancestry/page12.htmlhttp://www.tutorgig.com/ed/Haplogroup_R1b_(Y-DNA)
"R1b1b2a2c (M153): This haplogroup has been found so far in 39
individuals, most of them Basques; the rest were likely of Iberian
ancestry or have not been classified ethnically[18]. The first time
it was located (Bosch 2001[19]) it was described as H102 and included
7 Basques and one Andalusian.
R1b1b2a2d (SRY2627 or M167): The first author to test for this marker
(long before modern haplogroup nomenclature existed) was Hurles in
1999[20]. He found it relatively common among Basques (13/117: 11%)
and Catalans (7/32: 22%). Other occurrences were found among other
Spanish, Béarnais, other French, British and Germans.
In 2000, Rosser[21] also tested for that same marker, naming the
haplogroup Hg22, and again it was found mainly among Basques (19%),
in lower frequencies among French (5%), Bavarians (3%), Spanish (2%),
Southern Portuguese (2%), and in single occurrences among Romanians,
Slovenians, Dutch, Belgians and English.
In 2001, Bosch[22] described this marker as H103, in 5 Basques and 5
Catalans. Further regional studies[23] have located it in
significative amounts in Asturias, Cantabria and Galicia, as well as
again among Basques. Cases in the Azores and Latin America have also
been reported. A total of 85 individuals with this haplogroup have
been found so far, almost all of them in academic studies, making it
the best documented R1b1b2 subclade[24]."