Am I able to download my raw data?

Family Tree DNA does not have a file format for Y-chromosome DNA single nucleotide polymorphism (SNP) results. However, your raw data, the actual values for each […]

Do SNPs ever “mutate back?”

Yes. It is possible that a SNP will back mutate (change back). However, SNPs are slow changing. Thus, back mutations are uncommon.

Are Y-DNA haplogroups the same as mtDNA haplogroups?

No, the names in the mitochondrial DNA (mtDNA) haplogroups do not correspond with the same names in the Y-chromosome DNA (Y-DNA) haplogroups.    

How often does FamilyTreeDNA update their tree?

FamilyTreeDNA updates the phylogenetic tree when we have substantial evidence that there is a new branch or a new placement for a branch.

How are haplogroups and their subclades named?

Y-Chromosome DNA (Y-DNA) haplogroups and subclades names follow the conventions of the Y-Chromosome Consortium’s (YCC). The YCC short form names haplogroups with the first letter from the […]

How does Y-chromosome DNA (Y-DNA) haplogroup prediction work?

At Family Tree DNA, a Y-DNA haplogroup prediction is calculated using genetic distance. The calculation finds your most likely haplogroup. The prediction program compares your […]

How do I know which SNPs make sense for me to order?

Please order SNPs with the help of an expert if you aren’t sure which SNP(s) will benefit your research. Before ordering, you should ask the […]

What is the geographic and historic origin of my Y-chromosome DNA (Y-DNA) haplogroup?

The following descriptions provide brief overviews of each haplogroup’s origin and geographic distribution. Haplogroup A Haplogroup A is the first Y-chromosome lineage to diverge, from […]

Do I have to order a Y-chromosome DNA (Y-DNA) STR test before I take a SNP test?

Yes. If you do not have a Y-DNA STR test, you will not be able to view your haplotree information. Alternatively, you may first take […]

Can I skip extensive SNP testing and just test for a downstream Advanced Order SNP? If I am positive, may I assume that I also have all the SNPs above it?

It is possible to order Advanced SNPs in this way. We advise that you do not unless another closely related male from your surname group […]

How many generations do the Y-chromosome DNA (Y-DNA) SNP tests trace?

The Y-DNA tree begins with the common paternal ancestor to all men alive today. Therefore, Y-DNA haplogroups and the Y-DNA haplogroup testing (like Big Y […]

Are Y-chromosome DNA (Y-DNA) SNPs ever related to recent times and genealogy? Are they always for historic periods and more ancient ancestry?

Y-chromosome DNA SNPs (single nucleotide polymorphisms) are not always from anthropological or even historic times. Some Y-chromosome DNA SNPs are restricted to a single family […]


I believe that I have found an error in the FamilyTreeDNA Y-DNA Haplotree. Who should I contact?

If you have found a problem with our Y-DNA Haplotree, please use our contact form to submit a request to customer service. Include in your message […]

When comparing genetic distance between people, which is more important to look at SNPs or STRs?

SNPs (single nucleotide polymorphisms) offer a definitive answer to a potential relationship. When one person is positive (derived) for a SNP and the other person […]


What are the differences between SNPs and STRs?

A SNP is a single nucleotide polymorphisms. That means that it is a single small change in your DNA code. These changes are rare. Once […]


I also tested at another company. They placed me in a different haplogroup. How can this be?

The reason for conflicting results depends on the test performed by the other company. They may be providing a haplogroup prediction based on your STR […]

What is the difference between a Y-chromosome DNA (Y-DNA) SNP test and FamilyTreeDNA’s Y-DNA STR tests?

The Y-DNA SNP testing provides information on the deeper ancestry for a Y-chromosome DNA (Y-DNA) paternal lineage. Depending on the branch of the Y-DNA tree […]


Is a Y-chromosome DNA (Y-DNA) SNP test medical?

No.  Y-DNA SNP testing is not designed to give medical information.


I have limited DNA testing funds. What’s my best strategy? Should I upgrade to more markers or do SNP testing?

The answer to this depends on your personal interest. If you are interested in your ancestry that goes beyond where traditional paper trails end, you […]


I have already taken a Y-chromosome DNA (Y-DNA) STR test. Why do I need to take a SNP test? What more can it show me?

Ordering a Y-chromosome DNA (Y-DNA) SNP test will tell you more about your deeper ancestry. That is, the historic migrations of your direct paternal ancestors. […]


If Y-chromosome haplogroups change, does that mean my results are wrong or inconclusive?

No. Y-chromosome DNA SNP (single nucleotide polymorphism) test results are definitive. They are not subject to change. It is the name of the haplogroup to […]

What was the first version of the Y Chromosome Consortium’s phylogenetic tree?

The first version of the Y Chromosome Consortium’s (YCC) tree was the YCC 2002 tree. The University of Arizona’s YCC website has additional information about […]

When should I take a Y-DNA haplogroup test?

The need to test for your Y-Chromosome DNA (Y-DNA) haplogroup depends on your research interests. Taking an extended Y-DNA SNP test such as the Geno […]

On the Y-DNA – Haplotree page, what do the letters and numbers in the Haplogroup Information box mean?

We show the SNP (single nucleotide polymorphism) results from our Y-DNA SNP tests (transferred Geno 2.0, Advanced SNP, Backbone, or old Deepclade) under the Haplotree […]

On Public Project Websites, why are some haplogroups shown in red? Why are other haplogroups shown in green?

On Public Project Websites, a Y-chromosome DNA (Y-DNA) haplogroup is shown in red when it has been predicted using our haplogroup determination program. A Y-DNA haplogroup is shown […]

Should I test my Y-chromosome (Y-DNA) haplogroup?

If your interest is in your ancient ancestry and historic migrations then an extensive Y-DNA SNP test for your haplogroup such as the Geno 2.0 […]

What is the difference between a Y-chromosome DNA (Y-DNA) haplogroup project and a surname or paternal lineage project?

Both types of group projects look at the direct paternal lineage. However, they have different starting points. A Y-chromosome DNA (Y-DNA) haplogroup project starts from the founding […]

What is a Y-chromosome DNA (Y-DNA) haplogroup project?

A Y-DNA haplogroup project is a group project based on the results of Y-chromosome DNA (Y-DNA) tests. It is dedicated to studying one haplogroup or one haplogroup’s subclades […]

What does a Y-chromosome DNA (Y-DNA) haplogroup tell us?

Haplogroups and their subclades (branches) mark human migrations. Thus, learning about haplogroups can tell you about your ancestors’ history and travels.

What is a Y-chromosome DNA (Y-DNA) haplogroup?

Y-chromosome DNA (Y-DNA) haplogroups are the major branches on the human paternal family tree. Each haplogroup has many subbranches known as subclades.