Listing Criteria for SNP Inclusion
into the ISOGG Y-DNA Haplogroup Tree

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

LINKS:  Main Page   Y-DNA Tree Trunk   SNP Index   Papers Cited   Glossary  

These recommendations are to assure that there is a uniform set of criteria for accepting SNPs for placement on the ISOGG Y-DNA Haplogroup Tree. We would like to avoid the inclusion of new SNPs where it is not clear how they relate to previously established SNPs.

The supporting information should demonstrate that the new SNP is downstream of an established SNP and has been tested in individuals who have also tested for all potential (well established and non-private) downstream SNPs.

For example, suppose that a new SNP is discovered and that it is claimed to be 1) within Haplogroup F and 2) ancestral to both Haplogroups G and H, but not to I, J, or K. Then several persons should have been tested to demonstrate that those who are confirmed as being in either Haplogroup G or Haplogroup H are also derived for the new SNP, and that at least two persons who are in each of Haplogroups I, J, and K are ancestral for the new SNP. The individuals tested in each group also need to be unrelated. The test for this will be the provision of an associated STR profile that differs in at least 15% of the markers.

In the case where the new SNP is the terminal branch of an existing clade that already has existing sub-branches, then at least 2 individuals need to be tested from every existing sub-branch (i.e. sister clades of the new SNP), with the exception of private SNPS (defined below).

In the case where the new SNP is the new terminal sub-branch of an existing terminal SNP, then it should also be demonstrated that it is not restricted solely to close relatives. This can be achieved by demonstrating that two or more derived state individuals have greater than 15% mismatches in their associated STR profiles, and also results from at least 2 ancestral state SNPs.

The ISOGG committee will accept proposed new SNPs in a two-step process. First the discoverer of the SNP (or a third party, knowledgeable about the SNP) can email Whit Athey or John McEwan and describe where the new SNP fits in the cladogram. The committee can tentatively incorporate this SNP according to this advice and make any structural changes to the haplgroup tree necessitated by it. The discoverer (or third party) then would provide the evidence as stated above for the proposed placement within the period of one month. At the end of this time the SNP would be classified as either added (full confirmation) if full evidence as described above was available or confirmed (within subclade) if sufficient information was available to meet that requirement (see below). In the latter case it would be expected that when sufficient additional evidence was collected it would be provided and the SNP would move to added (full confirmation).

Provisional SNPs are color coded and defined as: SNPs newly submitted to the ISOGG committee that have sufficient information to be placed in the tree with some certainty, but insufficient to meet all the criteria above and are awaiting evidence as described above.

Confirmed SNPs are color coded and defined as: SNPs that have at least 20 individuals tested within their final subclade, plus at least 2 derived individuals. However, derived individuals for all existing branches within the subclade Ii.e. sister clades) have yet to be tested.

Private SNPs are color coded and are defined as:
   a) A SNP that has been observed only once, or has been observed multiple times but the associated STR profiles show less than 15% of markers have diverged
   b) A SNP for which NO specified population have been demonstrated to exist where the frequency is greater than 0.05% (P<0.05) and whose total male population exceeds 500 thousand individuals as defined geographically or ethnically.

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

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