H45b (Mitochondrial DNA)

H45b is considered a minor sub clade of the large haplogroup H.

H is the most common haplogroup of people of European descent through their matrilineal line ( ie mother, her mother, her mother etc) with around 40% of these being H. It is also common in North Africa, Central Asia and the Middle East. It was believed to have formed about 25 to 30 thousand years ago in the Middle East and entered Europe probably prior to the major Ice age which ended around 10,000 years ago with further migrations of different H sub clades into Europe post the ice age amongst Neolithic farming people, again from the middle East.

H45b is one of two known sub groups of H45 the other being H45a. H45 and H45a seem to be concentrated in Scandinavia whereas the H45b sub clade is found in North West Europe, Scandinavia, UK and Ireland as well as among descendants of people who migrated from these places. These H45 sub clades have only been recently (2012?) identified and are currently only known amongst people who are European through their mother's line.

One theory is that the H ancestresses remained in Europe through the ice age in an area close to the border of France and Spain and then moved north as the ice retreated. H45 is thought to have emerged approx. 8000 years ago from an H mother with H45b and H45a emerging more recently from H45 mothers. However the remains of early humans from the time of this ice age that have been able to be tested for MtDNA have not yet yielded any specific H MTDNA but only U MtDNA. On the other hand maps of the amounts of modern people having the H MtDNA show that they are most common in Spain/ France and reduce in numbers as distance increases implying that this area is probably a main migration source of the H haplogroup post the last main Ice age.

see http://www.eupedia.com/europe/Haplogroup_H_mtDNA.shtml