Scientists believe that haplogroup I originated with the Gravettian culture of Paleolithic Europe.
A newly identified subclade, I2b, which has occasionally been mistaken for a variant of haplogroup G
in previous studies, occurs in parts of Northern Ireland and Western Scotland, as well as in the Northern
Germanic parts of Europe.
Like I1, I2b is believed to have originated during the Paleolithic, and to have taken refuge
from the Ice Age in Iberia. Afterwards, it spread into other portions of Europe,
especially The Low Countries, Germany and, possibly, the British Isles.
Many of the Celts who colonized the British Isles from continental Europe may have
belonged to I2b. I2b may even have come to the British Isles far earlier.
The Caledonians, a Pictish tribe that was defeated by Agricola at the battle of
Mons Graupius, were described as Germanic in appearance. Other tribes were
described as dark and Iberian. This anecdotal evidence of an ethnic difference
among the aborigines of Britain does suggest a mixture of haplogroups in their ancestry.
It also supports the coexistence of both "Iberian" R1b and "Germanic" I2b on British
soil prior to either Roman or Anglo-Saxon colonization.
(For more information on the various subclades of haplogroup I, read this excellent study.)
I2b Haplotype #17
This haplotype shows its highest frequencies is parts of Spain once occupied by the Visigoths,
and in Western Norway.
This haplotype may have come to Britain with the Norse Vikings, or with the Normans,
whose troops and supporters included many of Visigothic as well as of Norse descent.
I2b Haplotype #19
This haplotype is uncommon, and its match pattern is too scattered to suggest
a particular ancestry. It appears vaguely Germanic, however, and may have come
to Britain with the Normans or the Anglo-Saxons.
|Sao Paulo, Brazil [European]||.22|
I2b Haplotype #20
The appearance of Ireland and Portugal among the higher frequencies
is more typical of an R1b haplotype. This is suggestive of a Celtic origin.
However, some of the other matches suggest that an alternate origin in
the Balkans or Western Germany. This haplotype may, in that case,
have spread to Iberia with the Suevi or the Visigoths - and to
Ireland with the descendants of the Normans or the Anglo-Saxons.
|Sao Paulo, Brazil [European]||1.54|
|Cape Town, South Africa [European]||1.00|
|Rio de Janeiro, Brazil [European]||.79|
I2b Haplotype #21
This is a rare haplotype, but the top hits are in Northern and Western Germany.
This haplotype most likely came to Britain with the Anglo-Saxons.