What is Y-DNA?

Y-DNA is passed down from father to son, so if you are a male, you will have received your Y-DNA from your father's father's father etc. It can be used to connect with distant cousins on the direct male line. Because the surname is also passed down from father to son, Y-DNA can be very useful for people who are researching a particular surname and is used quite frequently in One-Name Studies.

The Y-DNA test has a "reach" of about 330,000 years and so can also be used for exploring the deep ancestry on your direct male line (your father's father's father etc). This will give you an indication of  the route that your ancestors took during the last major human migration out of Africa.


  1. How do I convert yDNA test results from my late cousin's 2006 Relative Genetics 43-marker test to my 2017 FTDNA 111-marker test? At DYS452 he is 6 and I am 25. At DYS463 he is 20 and I am 22.

    1. Good question. I have had this problem occasionally before and the following links were helpful. But for a definitive answer, you may have to ask the company involved to ask their science team ...

  2. I've read through some of your articles and countless others comparing this test to that test, and honestly I'm still confused so I hope you'll forgive my DNA naivete! :-)
    My mom, her father, my sister and I have all done the Ancestry autosomal DNA test and transferred raw files to Family Tree DNA and GEDmatch. I want to find out more on my grandfather's paternal line, but since he has recently passed away, I'm guessing we would need to test my uncle going forward. I like seeing family matches, but my main 'wants' with this Y-DNA test is to hopefully break through a brick wall we have on that line at my 8th great grandfather and also to find deeper heritage info (grandpa said we're Scottish but I have not found that link yet) and hopefully this would also help the Robinson project I joined on Family Tree DNA. There are so many tests, I really don't know which one or combination would be best. Any advice? I was looking at something called Big Y but apparently you can only get that after doing another test?

    I'm also interested in my own paternal line and since my father and uncles are all gone, I would have to test my last remaining male first cousin. I would really like family matches as well as a deeper analysis. This line is of Japanese heritage and I don't know anything before my great grandparents.

    Lastly, I want my mother to do an mtDNA test to get a deeper look at that line. We do know that line is Norwegian but I'd love to know as much as I can about that and any ancient origins.

    Also, it seems as though haplo group info could be useful but not all tests provide that information. How important is it?

    I truly appreciate any help, especially in layman's terms.

    Thanks so much!!

  3. Certainly test your uncle with the Y-DNA-37 test and join the relevant Surname Project - the Admin will give further specific advice.

    Autosomal DNA tests will not reach as far back as your 8th great grandfather - they only connect you with cousins with whom you share a common ancestor about 5-7 generations ago.

    Similarly, do a Y-DNA-37 as the starter test for your own direct male line. And join relevant surname and haplogroup and geographic projects thereafter. The Admins will provide further guidance on next steps.

  4. I have my Y-STR DNA results. I belong to Haplogroup R1b and need your guidance to take my results to the next stage so that I can compare my results with other relatives if this is possible!

  5. I recently got my results back from FamilyTreeDNA for Y-67. I belong to Haplogroup I-M253. However, my first question is I keep seeing articles about surname. I have my mother's maiden name since my parents were not married at the time.

    Therefore, even though my last name is Northfield. My father's is Gross. I assume, I follow Gross for the Y articles whenever they mention same surname?

    Also, FamilyTreeDNA is offering an upgrade to test an additional 174 SNPs for $99. I am not sure if I truly need this or not in regards to my Haplogroup.