Haplogroup E3b (Y-DNA)

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E3b Prevalent in East Africa, particularly among Somalis and Borana people

In human genetics, Haplogroup E3b (M35) (previously called Hg21) is a Y-chromosome haplogroup with a distribution spreading from Africa around the Mediterranean into Europe and the Middle East. It is defined by the Single nucleotide polymorphism (SNP) mutations M215 and M35, which are almost always found together.

E3 (defined by SNPs P2, DYS391p) is a branch of the African haplogroup E (defined by SNPs SRY4064 (SRY8299 or M40), M96, P29). The other main branch of E3 is E3a, defined by SNPs M2 (SY81) (DYS271), M180, P1, P46.

E3b is believed to have first appeared in the Horn of Africa approximately 26,000 years ago and dispersed to the Middle East during the Upper Paleolithic and Mesolithic periods. From there, it traveled north and west with the expansion of Neolithic agriculturalists.

Outside of East Africa, its two most prevalent clades are:

1 E-M78 (E3b1a)
2 E-M81 (E3b1b, formerly E3b2)
3 See also
4 References
5 External links

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E-M78 (E3b1a)

This haplogroup arose ca. 18.6 kya after the spread of E3b1* (E-M35) from the Horn of Africa to Egypt, and has been further divided into subclades by Fulvio Cruciani, on the basis of the following SNP mutations...

E-V12* The oldest sub-clade, found mainly in Southern Egyptians (arose ca. 15.2 kya). Formerly comprised a few of Cruciani's delta cluster.
E-V13* The most prevalent clade in Europe, having first arose in West Asia ca. 11.5 kya, and equivalent with Cruciani's alpha cluster.
E-V22* Prevalent in East Africa and Egypt, with higher microsatellite variance (0.35 vs. 0.46, respectively) in Egypt, comprising most of those classified in Cruciani's earlier delta cluster.
E-V32* Prevalent in East Africa, particularly among Somalis and Borana Oromos, formerly defined as the gamma cluster (arose ca. 8.5 kya).

The most commonly distributed E3b sub-branch is E-M78. The flow of E3b can be summerized into about four main episodes, based on geographic and quantitative analysis of haplogroup and micro satellite diversity:

1) Sometime in the Upper Paleolithic, between 23.9 and 17.3ky ago, E3b (M215) bearing chromosomes were introduced to northeast Africa from sub-Saharan East Africa.

2) The M78 mutation (E3b1) then occurred in the E3b chromosomes distributed in Northeast Africa, to be followed by a back-migration episode to sub-Saharan East Africa, sometime between 18ky and 5.9ky ago. Some chromosomes which had acquired the M78 mutation in Northeast Africa undoubtedly also made their way westward in North Africa.

3) Sometime around 13ky ago,these M78 bearing E3b chromosomes were introduced to Europe directly from northern Africa.

4) Between 20 and 6.8ky ago, M78 bearing E3b chromosomes were introduced into western Asia from Northeast Africa. Crucian et al. 2007

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E-M81 (E3b1b, formerly E3b2)

E-M81 (E3b2; referred to as a "Berber marker"), which reaches frequencies of up to 80% in North Africa. It is thought of primarily as a Berber haplogroup, and is most common throughout the Maghreb region of North Africa.

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