Haplogroup L4 (mtDNA)

Haplogroup L4 is a human mitochondrial DNA (mtDNA) haplogroup. It is a small maternal clade primarily restricted to Africa.
L4 is important in East Africa and Horn of Africa. The highest frequencies are in Tanzania among the Hadza at 60-83% and Sandawe at 48%.
It has two branches, L4a and L4b. Subgroup L4a was formerly called L7 and considered a separate subclade of L3'4'7. It has been recognized as a subclade of L4, with L3 as its outgroup by Behar et al. (2008).
The parent clade L3'4 is to have emerged at 106–66 kya. 
L4 is not much later than this, estimated at 87 kya by Fernandes et al. (2015). 
Phylogeny.
The following phylogeny is based on van Oven and Kayser (2008). 