Haplogroup E3a is thought to be associated with the group that spread agriculture across the central and southern parts of Africa during the last 3000 years. The Bantu culture appears to have been the agent of the spread of this agricultural revolution. The Bantu Expansion shaped the language and culture of peoples throughout the western, central, and southern parts of the continent. That expansion also left a legacy of haplogroup E3a distributed across southern and central Africa. The distribution of E3a in Africa is shown as the green sections in the map on page 1204 of the study of African Y chromosomes by Cruciani et al.

The YSTR.org website has a graph showing the twenty most common haplotypes seen among 599 African-American men in the USA. The table below shows twelve haplotypes among those twenty that appear to belong to haplogroup E3a. It is interesting to note that there is enough diversity among the E3a's that most haplotypes differ at several markers from the most common haplotype. It appears that DYS390=21 and large alleles at DYS385 (for example, DYS385=16,17) may be distinguishing features of E3a haplotypes. The last line in the table is the five marker haplotype that Pereira et al identified as the founder haplotype of the Bantu.

Poloni et al and Passarino et al both found that about 70% of men from the Niger-Congo region showed a result of haplotype 4 (ht4) at the 49a,f Taq/I locus - so that is probably the usual result for E3a men. Scozzari et al found typical alleles of DYS413=20,22 and YCAII=19,19 or 19,21 among African E3a men.

M191 is a marker that will be useful for SNP testing among E3a men. Jobling et al listed the M191 subclade as E3a7 in their 2003 version of the YCC haplogroup tree. Cruciani et al found that 33% of all E3a's belonged to E3a7. They also saw a concentration of E3a7 in the Cameroon region that may indicate a western central Africa origin of that E3a subgroup.

Vallone and Butler found 58% of the 115 African Americans in the USA in their study were E3a, and another study by Paracchini et al found 49.6% of 247 African-Americans to be E3a.

Table 1. Twelve most common haplotypes seen among E3a African-Americans, and the founder haplotype of the Bantu.