This sub-clade of E-M35 was announced in Henn et al. (2008), which associated it with the spread of pastoralism from Eastern Africa into Southern Africa. So far high levels have been found in specific ethnic groups in Tanzania and Southern Africa. Highest were the Datog (43%), Khwe (Kxoe) (31%), Burunge (28%), and Sandawe (24%). Henn et al. (2008) in their study also found two Bantu-speaking Kenyan males with the M293 mutation.
Other E1b1b sub-clades are rare in Southern Africa. The authors state...
Without information about M293 in the Maasai, Hema, and other populations in Kenya, Sudan, and Ethiopia, we cannot pinpoint the precise geographic source of M293 with greater confidence. However, the available evidence points to present-day Tanzania as an early and important geographic locus of M293 evolution.
They also say that "M293 is only found in sub-Saharan Africa, indicating a separate phylogenetic history for M35* (former) samples further north".
The authors Henn et al. referred to this sub-clade with the proposed name E3b1f. However, this name was already out of date by the time the article was published since E1b1b1 had become the new YCC and ISOGG name for former E3b1, the clade defined by SNP M35. The sub-clade under E1b1b1 with the suffix "f" had also already been proposed in Karafet et al. (2008) for SNP P72 (see above). So the phylogenetic clade name came to be E1b1b1g in late October 2008. (For example the company Familytree DNA changed its webpages on or about 22 October and the relevant ISOGG reference page was changed on 23 October.)