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 SNP, will be available on the Y-DNA – Haplotree & […]

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 major haplogroup branch. This is followed by a dash and […]

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

At FamilyTreeDNA, a Y-DNA haplogroup prediction is calculated using genetic distance. The calculation finds your most likely haplogroup. The prediction program compares your Y-DNA STR (short tandem repeat) profile to our results database. The program […]

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 advice of an expert on your haplogroup and subclade. We recommend […]

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 which all Y-branches are descended. Haplogroup A is restricted to […]

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 and Geno 2.0) trace forward from our common paternal ancestor […]

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 the Geno 2.0 test and then transfer your results to […]

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 has already taken a more advanced SNP test such as […]

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 that is related in genealogical times (one to 15 generations). […]


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 the details of the problem and the FamilyTreeDNA kit number(s) […]

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 they happen, they seldom change back (back mutate). An STR […]


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 (short tandem repeat) results. The quality and size of their […]

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 to which the person tested belongs, this may relate to […]


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 should focus on SNP testing. If, however, your only interest […]


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. This extends what you have learned about your ancestry from […]


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 which you belong that has changed. This change reflects advances […]

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 the YCC 2002 tree.

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 2.0 test is a good idea for those interested in […]

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 tool in the Haplogroup Information box. The names of the […]

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 in green when it has been confirmed with a test […]

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 test is appropriate. Note that only one person in your […]

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 of a particular haplogroup or subclade. It traces that lineage […]

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 in all times and places.

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.