Haplogroup E (Y-DNA)

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In human genetics, Haplogroup E (M96) is a human Y-chromosome DNA haplogroup.

This haplogroup is found in Africa, the Middle East, and Europe. In Africa it is by far the most common haplogroup and is believed to have originated there some 50,000 years before present. Outside of Africa, Haplogroup E is found at moderate to low frequencies and largely belonging to the E3b subgroup.

Along with haplogroup D, E contains the distinctive YAP polymorphism, which indicates their common ancestry. Both D and E also contain the M168 change, which is present in all Y-chromosome haplogroups except A and B. A third YAP+ haplogroup (or, less likely, a paragroup), labeled provisionally as Haplogroup DE*, has been found at a very low frequency among the males of modern populations of Nigeria. It is important to note that haplogroup E is the only haplogroup belonging to the M168-tree that is present throughout Africa. All other branches coming from this lineage left Africa and gave birth to modern non-African human populations.

1 Origins
2 Subgroups
- 2.1 E1
- 2.2 E2
- 2.3 E3
3 References
4 External links

[edit] Origins

Bearers of haplogroup E were paleolithic hunters from the Sahara, probably creators of the so-called Aterian industry (aterien) that for the first time appears in the Maghreb (north-west Africa) 45-40 000 years ago and during the following milleniums was spread all over the Saharan plateau that was relatively wet at that time. When the Sahara began to desiccate 28 000 years ago, the bearers of this culture started to vacate this area and settled in more favourable regions. According to "genetic clocks," this is also the time when haplogroup E diverged into several subbranches. During the next milleniums these subbranches played a key role in the formation of the "Negroid race" as it is traditionally called today.

[edit] Subgroups

Subbranches include E1, E2, E3a (M2) and E3b (M35).

[edit] E1

E1 (M33) headed for West Africa and today it is mainly present in the region of Mali.

[edit] E2

E2 (M75) is present both in West and East Africa.

[edit] E3

E3, by far the most frequent subbranch of E, diverged into two main subbranches E3a (M2) and E3b (M35) approximately 24-27 000 years ago (Cruciani et al. 2004). The bearers of E3a populated the coastal region of West Africa, where they largely mixed with indigenous Pygmy populations and gave birth to modern West Africans speaking languages of the Niger-Congo family. As a result of the historical migrations of the agricultural Bantu that started ca. 3000 BC, E3a is the most frequent Y-haplogroup in Sub-Saharan Africa today. It is also the most common Y-haplogroup among African American men.

About 21-25 000 years ago the subbranch E3b arose in East Africa and spread northward into North Africa and West Asia, splitting further into another three haplogroups: haplogroup E3b3 spent the last ice age in the Levant and north-east Africa, E3b2 was present in the Maghreb and today it is the most important haplogroup of the Berbers (having arisen among the ancestral population to the Beta Israel, or Ethiopian Jews^[1]); E3b1 originated in East Africa and after the end of the ice age, it expanded north and west. The spreading of E3b1 is probably connected with the spread of the Afro-Asiatic languages.

The distribution of haplogroup E3b1 according to Semino et al. 2004

In populations of Europe, particularly among those that reside near the Mediterranean, Haplogroup E3b is believed to represent ancient genetic influence from East Africa, mediated by West Asian populations entering Europe during the Neolithic revolution (the spread of agriculture from Asia Minor). The subbranch E3b1 is present at high frequencies among the Greeks, Albanians, and South Italians (up to 25%), but its percentage gradually falls below 10% in the Carpathian basin and Iberia, and is negligible in other parts of Europe. Some E3b is instead explained by more recent genetic influence from North Africa.

[edit] References

^ S.O.Y. Keita, Explanation of the Pattern of P49a,f TaqI RFLP Y-Chromosome Variation in Egypt (2005)

B. Arredi et al.: A Predominantly Neolithic Origin for Y-Chromosomal DNA Variation in North Africa. American Journal Of Human Genetics, 2004, p. 338–345
F. Cruciani et al.: A Back Migration from Asia to Sub-Saharan Africa Is Supported by High-Resolution Analysis of Human Y-Chromosome Haplotypes. American Journal Of Human Genetics, 2002, p. 1197–1214
F. Cruciani et al.: Phylogeographic Analysis of Haplogroup E3b (E-M215) Y Chromosomes Reveals Multiple Migratory Events Within and Out Of Africa. American Journal Of Human Genetics, 2004, p. 1014–1022
F. Cruciani et al.: Molecular Dissection of the Y Chromosome Haplogroup M-78
J. R. Luis et al.: The Levant versus the Horn of Africa: Evidence for Bidirectional Corridors of Human Migrations. American Journal Of Human Genetics, 2004, p. 523-544
J. J. Sanchez et al.: High frequencies of Y chromosome lineages characterized by E3b1, DYS19-11, DYS392-12 in Somali males. European Journal of Human Genetics, 2005, p. 856–86
A. Salas et al.: The Making of the African mtDNA Landscape. American Journal Of Human Genetics, 2002, p. 1082–1111
O. Semino et al.: Origin, Diffusion, and Differentiation of Y-Chromosome Haplogroups E and J: Inferences on the Neolithization of Europe and Later Migratory Events in the Mediterranean Area. American Journal of Human Genetics, 2004, p. 1023-1034
E. T. Wood et al.: Contrasting patterns of Y chromosome and mtDNA variation in Africa: evidence for sex-biased demographic processes. European Journal of Human Genetics, 2005, p. 867–876