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CLADE/SUBCLADE SYMBOLS: Added Redefined |
SNP SYMBOLS: Not on 2007 tree Confirmed within subclade Provisional Private |
B M60, M181, P85, P90
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B* -
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B1 M236, M288
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B1* -
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B1a M146
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B2 M182
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B2* -
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B2a M150
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B2a* -
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B2a1 M218
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B2a1* -
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B2a1a M109, M152, P32, P50
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B2a2 M108.1
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B2a2* -
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B2a2a M43, P111
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B2b M112, M192, 50f2(P)
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B2b* -
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B2b1 P6
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B2b2 M115, M169
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B2b3 M30, M129
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B2b3* -
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B2b3a M108.2
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B2b4 P7
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B2b4* -
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B2b4a P8, P70
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B2b4b MSY2.1, M211
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B2c P112
Y-DNA haplogroup B, like Y-DNA haplogroup A, is seen only in Africa and is scattered widely, but thinly across the continent. B is thought to have arisen approximately 50,000 years ago. These haplogroups have higher frequencies among hunter-gather groups in Ethiopia and Sudan, and are also seen among click language-speaking populations. The patchy, widespread distribution of these haplogroups may mean that they are remnants of ancient lineages that once had a much wider range but have been largely displaced by more recent population events.
Some geographic structuring is seen between the sub-groups B2a (B-M150) and B2b (B-M112). Sub-group B2b is seen among Central African Pygmies and South African Khoisan. Sub-group B2a is seen among Cameroonians, East Africans, and among South African Bantu speakers. B2a1a (B-M109) is the most commonly seen sub-group of B2a. About 2.3% of African-Americans belong to haplogroup B - with 1.5% of them belonging to the sub-group B2a1a.
References:
Cruciani et al,
A Back Migration from Asia to Sub-Saharan Africa Is Supported
by High-Resolution Analysis of Human Y-Chromosome Haplotypes. (pdf)
American Journal of Human Genetics, 70:1197-1214, 2002.
Karafet et al,
New Binary Polymorphisms Reshape and Increase Resolution of the Human Y-Chromosomal Haplogroup
Tree. Abstract. Genome Research, published online April 2, 2008.
Supplementary Material.
Regueiro et al,
Iran: Tricontinental Nexus for Y-Chromosome Driven Migration. (abstract)
Human Heredity, Vol. 61, No 3, 132-143, 2006.
Semino et al,
Ethiopians and Khoisan Share the Deepest Clades of the Human Y-Chromosome Phylogeny. (pdf)
American Journal of Human Genetics, 70:265-268, 2002.
Valone et al,
Y SNP Typing of African-American and Caucasian Samples Using Allele-Specific
Hybridization and Primer Extension. (pdf) Journal of Forensic Science, 49:4, July 2004.
Corrections/Additions made since 31 December 2007:
Contact Person for Haplogroup B: Ana Oquendo Pabon
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