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Y-DNA haplogroups are groups that share a common ancestor having the same single nucleotide polymorphism (SNP) mutation. Unlike mtDNA, which is passed down the matrilineal line, Y-DNA is passed solely along the patrilineal line, from father to son. Y-DNA can provide insight into both recent genetic ancestry via short tandem repeats (STRs) and ancient human migratory patterns via SNPs.

Haplogroup projects

Y-DNA haplogroups are named from A to T, and are further subdivided using numbers and lower case letters.


Terminal SNPs

The y-DNA projects on Geni use a system called Terminal SNPs. This system refers to each subgroup by the identifier of its SNP mutation rather than by its haplogroup. This system makes it easier to accommodate the frequent changes to the nomenclature.

For more information, see Your Genetic Genealogist, Let's All Start Using Terminal SNP Labels Instead of Y Haplogroup Subclade Names, Okay? (Sept. 20, 2012).

How to participate

To participate in this project, join or follow any of the haplogroup projects, then add your oldest known ancestor who belonged to that haplogroup. The profile must be set to public in order to add it.

Creating sub-projects

If your ancestor belonged to a group that doesn't have a project, send a message to one of this project's collaborators. We'll create a project for you.

Or, follow these steps to create the project yourself:

  1. Use the FTDNA Draft Tree to be sure you're using the right name.
  2. Create the project. The standard name format for yDNA projects is R-U106 (Y-DNA).
  3. Drop in the standardized headings (Defining Mutations, Origin, Distribution, Subclades, Famous Members, How to Participate, Resources)
  4. Add the new project to this Y-DNA Haplogroups page.
  5. Copy the group of links for the entire haplogroup to the Subclades section of all its sub-projects.
  6. Add the yDNA master project and all of that haplogroup's sub-projects as Related Projects.


  1. Post a question about genetic genealogy here
  2. Post a question about DNA testing here
  3. Post a question about yDNA projects here
  4. Or, send a message to any of the following curators:

External links