Haplogroup E-M2

Haplogroup E-M2, also known as E1b1a1-M2, is a human Y-chromosome DNA haplogroup. E-M2 is primarily distributed within sub-Saharan Africa. More specifically, E-M2 is the predominant subclade in West Africa, Central Africa, Southern Africa, and the region of the African Great Lakes; it also occurs at low to moderate frequencies in North Africa, and at low frequencies in the Middle East. E-M2 has several subclades, but many of these subhaplogroups are included in either E-L485 or E-U175. E-M2 is especially common among indigenous Africans who speak Niger-Congo languages, and was spread to Southern Africa and East Africa through the Bantu expansion. The discovery of two SNPs (V38 and V100) by Trombetta et al. (2011) significantly redefined the E-V38 phylogenetic tree. This led the authors to suggest that E-V38 may have originated in East Africa. E-V38 joins the West African-affiliated E-M2 and the Northeast African-affiliated E-M329 with an earlier common ancestor who, like E-P2, may have also originated in East Africa. The downstream SNP E-M180 may have originated in the humid south-central Saharan savanna/grassland of North Africa between 14,000 BP and 10,000 BP. According to Wood et al. (2005) and Rosa et al. (2007), such population movements changed the pre-existing population Y chromosomal diversity in Central, Southern, and Southeastern Africa, replacing the previous haplogroup frequencies in these areas with the now dominant E1b1a1 lineages. Traces of earlier inhabitants, however, can be observed today in these regions via the presence of the Y DNA haplogroups A1a, A1b, A2, A3, and B-M60 that are common in certain populations, such as the Mbuti and Khoisan. Shriner et al. (2018) similarly suggests that haplogroup E1b1a-V38 migrated across the Green Sahara from east to west around 19,000 years ago, where E1b1a1-M2 may have subsequently originated in West Africa or Central Africa. Shriner et al. (2018) also traces this migration via sickle cell mutation, which likely originated during the Green Sahara period.