L2a1a is defined by a mutation at 16286. The L2a1a founder candidate dates to 2,700 (SE 1,200) years ago. (Pereira et al. 2001). However, L2a1a, as defined by a substitution at (np 16286) (Salas et al. 2002), is now supported by a coding-region marker (np 3918) (fig. 2A) and was found in four of six Yemeni L2a1 lineages. L2a1a occurs at its highest frequency in Southeastern Africa (Pereira et al. 2001; Salas et al. 2002). Both the frequent founder haplotype and derived lineages (with 16092 mutation) found among Yemenis have exact matches within Mozambique sequences (Pereira et al. 2001; Salas et al. 2002). L2a1a also occurs at a smaller frequency in North West Africa, among the Maure and Bambara of Mali and Mauritania. (Rando "et al." 1998; Maca-Meyer "et al." 2003)