Haplogroup L2
Its L2a subclade is a somewhat frequent and widely distributed mtDNA cluster on the continent, as well as among those in the Americas.
[1] Its age and widespread distribution and diversity across the continent makes its exact origin point within Africa difficult to trace with any confidence.
This implies that, at least in the early stages, the Bantu expansion was mainly a demic diffusion with little incorporation of local populations".
It is particularly abundant in Chad and the Kanembou (38% of the sample), but is also relatively frequent in Nomadic Arabs (33%)[10][5] and Akan people (~33%)[11] L2a L2b L2c L2d L2e L2 has five main subhaplogroups: L2a, L2b, L2c, L2d and L2e.
[12] Haplogroup L2 has been observed among specimens at the island cemetery in Kulubnarti, Sudan, which date from the Early Christian period (AD 550–800).
[16] The wide distribution of L2a and diversity makes identifying a geographical origin difficult.
The main puzzle is the almost ubiquitous Haplogroup L2a, which may have spread East and West along the South East Africa Corridor in after the Last Glacial Maximum, or the origins of these expansions may lie earlier, at the beginnings of the Later Stone Age ~ 40,000 years ago.
[15] Haplogroup L2a also appears in North Africa, with the highest frequency 20% Tuareg, Fulani (14%).
[17][18] In patients who are given the drug stavudine to treat HIV, Haplogroup L2a is associated with a lower likelihood of peripheral neuropathy as a side effect.
However, whereas the majority (26 out of 33) Afro Americans share Haplogroup L2a complete sequences could be partitioned into four subclades by substitutions at nps L2a1e-3495, L2a1a-3918, L2a1f-5581, and L2a1i-15229.
[20] Haplogroup L2a1 has been found in ancient fossils associated with the Pre-Pottery Neolithic culture at Tell Halula, Syria.
[21] A specimen excavated at the Savanna Pastoral Neolithic site of Luxmanda in Tanzania also carried the L2a1 clade.
There are two L2a clusters that are well represented in southeastern Africans, L2a1a and L2a1b, both defined by transitions at quite stable HVS-I positions.
The very recent starbursts in subclades L2a1a and L2a2 suggest a signature for the Bantu expansions, as also proposed by Pereira et al. (2001).
L2a1a also occurs at a smaller frequency in North West Africa, among the Maure and Bambara of Mali and Mauritania.
It has been found in the United States[12] as well as Brazil,[24] Libya, Sierra Leone, Angola,[25] Zambia,[26] and other countries.
Positions T16209C C16301T C16354T on top of L2a1 define a small sub-clade, dubbed L2a1c by Kivisild et al. (2004, Figure 3) (see also Figure 6 in Salas et al. 2002), which mainly appears in East Africa (e.g. Sudan, Nubia, Ethiopia), among the Turkana and West Africa (e.g. Kanuri).
[27] (citation on page.9 or 443)[10][28] L2a1c has been shown to be present in Chad, Gabon, Spain, and the United States.
Branches also present in Latin America and West Africa, due to north African admixture.
Described as European-specific, it was previously called subclade L2a1a and has been detected in Czechs, Slovaks, Croatians, Serbs, and Bulgarians.
[40] L2a1l2a is recognized as an "Ashkenazi-specific" haplogroup, seen amongst Ashkenazi Jews with ancestry in Central and Eastern Europe.
It has also been detected in small numbers in ostensibly non-Jewish Polish populations, where it is presumed to have come from Ashkenazi admixture.
[43] However, this haplotype constitutes only a very small proportion of Ashkenazi mitochondrial lineages; various studies (including Behar's) have put its incidence at between 1.4–1.6%.
It has been found in Burkina Faso[44] and Haiti as well as Oman, Yemen, Saudi Arabia and Israel.
[45] This phylogenetic tree of haplogroup L2 subclades is based on the paper by Mannis van Oven and Manfred Kayser Updated comprehensive phylogenetic tree of global human mitochondrial DNA variation[3] and subsequent published research.
