Haplogroup B · Early African Lineage
Haplogroup B
Explore ancient paternal branches found among populations across Central, Eastern and Southern Africa.
Approximate region of emergence
Central and/or Eastern Africa
Estimated time depth
Roughly 90,000–130,000 years before present (range)
Ancestral parent lineage
BT (the branch that also leads to all non-African lineages)
Major descendant branches
B1 (B-M236) · B2a (B-M150) · B2b (B-M112)
Overview
What this lineage represents
Haplogroup B branches off very early in the human paternal tree, shortly after the split that separates the A lineages from everyone else. It is found essentially only in Africa.
B is most strongly associated with rainforest hunter-gatherer populations of Central Africa and with several groups in Eastern and Southern Africa, though it also appears at low frequency in many farming populations.
Its distribution is often read as a signal of pre-agricultural population structure that later expansions partly overwrote but never erased.
Lineage tree
From parent lineage to modern descendants
Select any node to read its estimated age, parent lineage, regions and descendant branches.
Ancient distribution
Where early carriers are believed to have lived
The internal structure of B2b suggests that Central African rainforest populations and Southern African forager populations were connected in the deep past and then separated for a very long time. Early carriers are inferred across the Congo basin, the East African Rift and parts of Southern Africa well before agriculture reached these regions.
Migration
Origin → Expansion → Migration → Modern distribution
Origin
~130,000–90,000 ybp
Early branching
B separates from the lineage leading to CT, remaining within Africa.
Expansion
~60,000–30,000 ybp
Forager networks
B2b diversifies across the Congo basin, the Rift Valley and Southern Africa.
Migration
~10,000–3,000 ybp
Contact with food producers
B2a is carried into new areas alongside expanding farming and herding populations, appearing at low frequency far from its earlier range.
Modern
Last 2,000 years
Persistence in refugia
B remains at high frequency mainly among rainforest and Kalahari forager-descended communities.
Estimated pathways
Modern distribution
Where major branches are documented today
West Africa
B2a (B-M150)
Low frequency across the region.
Central Africa
B2b (B-M112)
Frequently observed among Aka, Baka and Mbuti communities.
East Africa
B-M30, B2a
Observed among Hadza, Sandawe and Sudanic populations.
Southern Africa
B-M152, B2a
Observed among Khoe-San and some Bantu-speaking groups.
North Africa
B2a
Rare; linked to trans-Saharan connections.
African Diaspora
B2a
Low frequency in the Americas.
Outside Africa
—
Essentially absent outside Africa and its diaspora.
Major subclades
Downstream branches
| Branch | Marker | Regions | Note |
|---|---|---|---|
| B1 | B-M236 | West and Central Africa | Rare early branch. |
| B2a | B-M150 | Sub-Saharan Africa | Widely distributed low-frequency branch. |
| B2b | B-M112 | Congo basin, Rift, Kalahari | Forager-associated branch. |
| B2b1 | B-M30 | East Africa | Tanzanian click-speaking populations. |
| B2b4 | B-M152 | Kalahari | Southern African branch. |
Populations
Frequently observed in
These are populations in which particular branches have been reported. Each of them carries several paternal lineages; the listed branches are not a definition of the group.
Aka
Central Africa
B-M112 derived
Baka
Central Africa
B-M112 derived, E-M2
Mbuti
Central Africa
B-M112 derived
Hadza
East Africa
B-M30, A-M13
Sandawe
East Africa
B-M30, E-M2
Khwe
Southern Africa
B-M152, A-M51
A haplogroup traces one unbroken father-to-son line. It says nothing about the rest of a person's ancestry, and it is not a marker of ethnicity or identity.
Research notes
Where the science is still unsettled
- Whether B originated in Central or Eastern Africa is not settled; both scenarios fit current data.
- Frequencies among forager communities vary sharply between neighbouring groups, so single-village samples can be misleading.
- Low-level B in farming populations may reflect either ancient shared ancestry or more recent gene flow; the two are hard to distinguish from Y data alone.
Citations for this lineage
- Batini, C. et al. (2011). Signatures of the pre-agricultural peopling processes in Sub-Saharan Africa as revealed by the phylogeography of early Y chromosome lineages. Molecular Biology and Evolution
- Wood, E. T. et al. (2005). Contrasting patterns of Y chromosome and mtDNA variation in Africa. European Journal of Human Genetics
- Barbieri, C. et al. (2016). Genetic perspectives on the origin of clicks and Khoe-San population history. Human Biology / European Journal of Human Genetics
- Karafet, T. M. et al. (2008). New binary polymorphisms reshape and increase resolution of the human Y chromosomal haplogroup tree. Genome Research
- Poznik, G. D. et al. (2016). Punctuated bursts in human male demography inferred from 1,244 worldwide Y-chromosome sequences. Nature Genetics
Continue exploring
Ancient Lineage
Explore some of the deepest surviving branches of the human Y-chromosome tree.
CCoastal Aboriginal Lineage
One of the earliest lineages to leave Africa, carried along the southern coastal route to Arabia, South Asia, Australia and the Americas.
DDeep Relative Of E
The sister branch of haplogroup E within DE, today found in Tibet, Japan and the Andaman Islands, with rare deep African branches.
EThe African Macro-Lineage
Originated in Africa, yet the oldest indigenous paternal lineage in the Levant and Arabia as well; the most frequently observed paternal lineage in Africa and its diaspora; parent of both E1a and E1b.
E1aAfrican Expansion
A deep paternal lineage that traces an African origin through the Green Sahara, the Mediterranean world, and into the Sahel and West African empires.
E1bAfrica & Beyond
Explore a highly diversified lineage with branches distributed throughout Africa and neighbouring regions.
FRoot Of Most Non-African Lineages
The lineage from which G through T descend, accounting for the overwhelming majority of men outside Africa.