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This project is a meeting place for users who share the J2b Y-DNA haplogroup, which means they are related along their paternal lines. Users in this group may want to share their family trees with each other to find overlaps and merge duplicate profiles in order to join or expand the World Family Tree and discover new relatives.
This project is about a Y-haplogroup, which defines a group of men by a shared set of inherited features in the DNA of their Y-chromosome. This implies they have a patrilineal ancestor in common, because only males carry a Y-chromosome, which they inherit from their father. The major Y-haplogroups were formed thousands of years ago, and therefore each group can today include thousands to millions of men. For an introduction, you can visit the Y-DNA Haplogroups project, the DNA Testing project, or start at the beginning with the DNA Primer project.
This haplogroup project's name uses the older, now secondary, hierarchical format for Y-chromosome haplogroup names. Because the haplogroup names under this earlier system would change with the identification of new branches, it's no longer possible to know unambiguously to which current haplogroup this designation refers. Anyone with an old test result that assigned them to a Y-haplogroup with this name should update their information to use a shorthand format name that references a defining SNP.
The J2b haplogroup is descended from the J2-M172 haplogroup.
Naming Changes
Depending on when they were identified as J2b, people with this haplogroup assignment probably belong to either the J2-M68 haplogroup (FamilyTreeDNA 2005-2007) or the J2b-M102 (aka J2b-M12) haplogroup (FamilyTreeDNA 2008-2012) (source1, source2).
If you know your Y-DNA haplogroup only by the old-style "J2b" name, you should reexamine your haplogroup assignment with your Y-DNA test provider, or review the original data directly (see below), to definitively determine exactly within which haplogroup you belong under the new naming system. If you know what year the "J2b" assignment was made, it may be possible in some cases to use a conversion table to determine the SNP used to define that Y-haplogroup in the year your test was performed, and then work forward from the associated SNP to identify the appropriate modern haplogroup name.
SNP Results Diagnostic for J2-M68 vs. J2b-M102
The "J2b" designation has been used to indicate different haplogroups at different times, typically either J2-M68 and J2b-M102. By directly examining your individual SNP test data, you can determine in which haplogroup you belong under the current, non-ambiguous haplogroup naming scheme. Assuming that all past J2b assignees belong to one of these two haplogroups (a big assumption at this time!), here are the diagnostic SNPs to determine in which haplogroup a person belongs:
- J2-M68 SNPs: M172+ M410+ M68+ M102- M12- M314-
- J2b-M102 SNPs: M172+ M410- M68- M102+ M12+ M314+
For reference, as of Dec 2016 (source)...
The phylogenetic derivation of J2b-M102 from the J haplogroup is: J-M304 > J2-M172 > J2b-M102
The phylogenetic derivation of J2-M68 from the J haplogroup is: J-M304 > J2-M172 > J2a-M410 > J2a-L26 > J2a-M68