|Haplogroup E1b1a or E-M2|
|Time of origin||approx 20,000-30,000 years BP|
|Place of origin||West Africa|
|Descendants||E1b1a1, E1b1a2, E1b1a3, E1b1a4, E1b1a5, E1b1a6, E1b1a7, E1b1a8, E1b1a9|
|Defining mutations||DYS271/M2/SY81, M180/P88, P1/PN1, P46, P182, P189, P211, P293|
It can also be referred to with mutational nomenclature as E-M2.
It is sometime associated with Haplotype IV from Ngo and Lucotte nomenclature however it is not proved and the clues are weak.
Haplogroup E1b1a is the main haplogroup in sub-Saharan Africa, where it reaches frequencies of over 80% in West Africa. It has been hypothesized that E1b1a originated in Northern Africa and then spread to sub-Saharan Africa with the Bantu expansion . However, Rosa et al. (2007) and others suggest that it likely originated in and expanded from West Africa (i.e., the Sudanese Belt) within the last 20,000 to 30,000 years based on the fact that the frequency and diversity of E1b1a in this region are among the highest found. E-M2 is considered to be the signature Y-DNA for the Bantu expansion, however, it should be considered the signature y-DNA for the Niger-Congo phylum or language, which means that E1b1a was probably the most common chromosome in West Africa when the Niger-Congo language emerged at least 15,000 YBP(years before present).
There exists a west-to-east as well as a south-to-north clinal distribution with respect to E1b1a, in other words, the diversity and frequency increases as you move from East and North Africa to West and Southern Africa. . This is why it is observed in low frequencies in the Horn of Africa, North Africa, and Southwest Asia, where the E1b1b haplogroup has its highest frequencies, and its small presence in those areas is generally attributed to the slave trade and/or the Bantu expansion.
E1b1a is the single most common Y-chromosome haplogroup among people of Sub-Saharan African descent both inside and outside of Africa. It is observed at frequencies of 58%-60% in African Americans. The E1b1a subclades E1b1a7 and E1b1a8 are widely found throughout sub-saharan Africans. However, according to Karafet, E1b1a9 has been found only in one Gambian. The haplogroups E1b1a2, E1b1a3, E1b1a4, E1b1a5, and E1b1a6 are quite uncommon as well.
This phylogenetic tree of haplogroup subclades is based on the YCC 2008 tree  and subsequent published research.
|most recent common Y-ancestor|