Y-DNA Haplogroup A and its Subclades
The entire work is identified by the Version Number and date given on the Main Page.   Directions for citing the document are given at the bottom of the Main Page.
Version History     Last revision date for this specific page: 10 April 2006

Because of continuing research, the structure of the Y-DNA Haplogroup Tree changes and ISOGG does its best to keep the tree updated with the latest developments in the field. The viewer may observe other versions of the tree on the Web. Email Alice Fairhurst if the differences need clarification.

LINKS:  Main Page   Y-DNA Tree Trunk   SNP Index   Papers Cited   Glossary   Listing Criteria
SNP SYMBOLS:  Not on 2005 tree  Confirmed within subclade  Provisional  Private

A   M91
       A*   -
       A1   M31
       A2   M6, M14, M23, M49, M71, M135, M141, M196, M206, M212, MEH1, P3, P4, P5, PK1
             A2*   -
             A2a   M114
             A2b   P28
       A3   M32
             A3*   -
             A3a   M28, M59
             A3b   M144, M190, M220
                    A3b*   -
                    A3b1   M51
                    A3b2   M13, M63, M127, M202, M219, M305
                          A3b2*   -
                          A3b2a   M171
                          A3b2b   M118

Y-DNA haplogroup A represents the oldest branching of the human Y chromosome tree. Like Y-DNA haplogroup B, the A lineage is seen only in Africa and is scattered widely, but thinly across the continent. These haplogroups have higher frequencies among hunter-gather groups in Ethiopia and Sudan, and are also seen among click language-speaking populations. Their patchy, widespread distribution may mean that these haplogroups are remnants of ancient lineages that once had a much wider range but have been largely displaced by more recent population events.

The most commonly seen sub-groups of haplogroup A are A2 (A-M6), A3b1 (A-M51), and A3b2 (A-M13). Sub-groups A2 and A3b1 are seen in South Africa, with A3b1 seen exclusively among the Khoisan. The range of A3b2 is restricted to Eastern Africa and at lower frequencies among Cameroonians. About 1.1% of African-Americans belong to the sub-group A3b2.


Cinnioglu et al, Excavating Y-chromosome Haplotype Strata in Anatolia. (pdf) Human Genetics. 114:127-148, 2004.
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.
Deng et al, Evolution and Migration History of the Chinese Population Inferred from the Chinese Y-chromosome Evidence. (pdf) Journal of Human Genetics, 49:339-348, 2004.
Mohyuddin et al, Detection of Novel Y SNPs Provides Further Insights into Y Chromosomal Variation in Pakistan. Journal of Human Genetics, 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.
Shen et al, Reconstruction of Patrilineages and Matrilineages of Samaritans and other Israeli Populations from Y-Chromosome and Mitochondrial DNA Sequence Variation. (pdf) Human Mutation, 24:248-260, 2004.
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.

Contact Person for Haplogroup A: Dennis Garvey

Back to Main Page
Back to Y-DNA Tree Trunk
Back to SNP Index
Back to Papers Cited
Back to Glossary
Back to Listing Criteria

Copyright 2006, International Society of Genetic Genealogy. All Rights Reserved.