A haplogroup is a genetic population group of people who share a common ancestor on the direct paternal or maternal line. Haplogroups are assigned letters of the alphabet, and refinements consist of additional number and letter combinations.
Y chromosome DNA haplogroups
Y chromosome DNA (Y-DNA) haplogroups are determined by single-nucleotide polymorphism (SNP) tests. SNPs are locations on the DNA where one nucleotide has "mutated" or "switched" to a different nucleotide.
Because a haplogroup consists of similar haplotypes, it is possible to predict a haplogroup from the haplotype. A SNP test is required to confirm the haplogroup prediction. Not all the testing companies offer SNP testing, and consequently their customers' haplogroup predictions are sometimes inaccurate.
ISOGG maintains the most up-to-date version of the Y-SNP tree. The tree is updated as and when new branch-defining SNPs are discovered. The criteria for inclusion of SNPs in the tree are published here.
Y-DNA haplogroup prediction tools
- Whit Athey's haplogroup predictor
- Jim Cullen's haplogroup predictor
- Terry Robb's haplogroup I1 and I2 subclade predictor (for 67 marker results only)
- Vadim Urasin's Y-DNA haplogroup predictor
- The Genographic Project haplogroup prediction tool
- Predicting haplogroups in one-step Stephen P. Morse's haplogroup tool
Mitochdondrial DNA haplogroups
When you have taken a mitochondrial DNA (mtDNA) test most companies will give you a prediction of your mtDNA haplogroup. The haplogroup can however only be confirmed by testing specific haplogroup-defining single-nucleotide polymorphisms (SNPs), some of which are only found in the coding region. If no SNP tests are done there is a possibility that the prediction will be incorrect. mtDNA tests from Family Tree DNA (HVR1 and HVR2) and the Genographic Project version 1 (HVR1) include a panel of 22 SNPs to confirm the base haplogroup.
The most up-to-date version of the mtDNA tree is maintained by Mannis van Oven on the Phylotree website.
To check or predict a haplogroup assignment use James Lick's free mtHap tool.
- ISOGG Y-SNP tree
- Phylotree The phylogenetic tree of global human mitochondrial DNA variation
- FTDNA's list of mtDNA haplogroup-defining mutations
- Y-chromosome consortium
- Y-SNPs and haplogroups DNA Heritage masterclass N.B. DNA Heritage was acquired by Family Tree DNA in 2012.
- Y haplogroups of the world
- Y haplogroups brief descriptions and regional origins
- Wikipedia list of haplogroups of historical and famous figures
- Wikipedia page on human mitochondrial DNA haplogroups
- Wikipedia page on human Y-chromosome DNA haplogroups