Why Take a Y DNA Test

Diahan Southard

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Why take a Y DNA test? Here’s why YDNA testing is so popular—and 3 reasons to consider why you should do it (or have a male relative test) for your family history.

3 Reasons Take a YDNA Test IO.png The Y chromosome DNA test, more affectionately referred to as the Y DNA test, is the darling of the DNA testing industry. At least, I think so. In fact, of the three kinds of DNA tests, the YDNA is my favorite (but don’t tell the other two!). It has several excellent qualities that make it useful in many genealogical scenarios, but let’s look at three.

3 reasons to take a Y DNA test

1. You have a missing father on your family tree

Now, all of us should be able to identify with this genealogical problem. Every line in your family history has this problem at some point. Any ancestor whose father is currently unknown falls in this category.

And Y DNA can help.

The specific quality of Y DNA that makes it so attractive in this case is its faithfulness in passing down its record generation after generation, without fail, without changing, from one genetic male to the next. That means that any living male today has the same (or very similar) Y-DNA as every male in his direct paternal line, back 8, 10, 12+ generations. Therefore every man’s Y DNA is the clue that could lead you to discover that missing father. Usually what it takes is a match in the Y DNA database with another descendant of your common ancestor. Ideally, this person knows something that you don’t about that missing father, and the two of you can work together to verify and extend your family history.

Got a missing biological father of your own that you’re looking for? You’ll also want to check out our tips for finding a birth father.

Show me those tips!

2. Your relative is worried about privacy

While DNA testing has certainly entered a season of relative acceptance among genealogists, there are still many who wonder what the eventual ramifications of having your DNA tested might bring. While this is a subject that certainly deserves some attention, Y DNA is actually the easiest test to sell to a nervous relative. The very qualities that make YDNA testing valuable—namely that every male descendant of a given ancestor will have the same Y DNA—make it equally impossible to identify any particular individual uniquely. This means that the Y DNA record that is created when a man takes a Y DNA test cannot ever be traced back to him alone. That same record could have easily come from his brother or first (or 5th) cousin.

Similarly, the Y-DNA test results have only a tenuous link to your health. The regions that are tested are generally parts that are not useful for determining any kind of personal health or trait information. There have been a few claims here and there, but most are unsubstantiated or auxiliary without a direct link to the Y DNA test we take for genealogy.

3. You have a surname mix-up

One of the best applications of Y DNA testing comes when trying to disentangle the relationships of various men living in close proximity with other men of the same or similar surname. Having descendants of these men test their Y DNA is like traveling back in time and conducting personal interviews of each of these men. It’s like saying, “Excuse me, Mr. Moffat? Is this neighbor of yours, Mr. Moffit, your uncle?”

Wouldn’t you give anything for a chance to have that conversation? Well, Y-DNA testing gets you almost there. You might not be able to determine if they are uncle and nephew, but you will at least know if they are kin.

The bonus quality of Y DNA is that it is only offered at one testing company, FamilyTreeDNA.* So you don’t even have to decide where to be tested. Your biggest decision will be in determining what level of testing to choose. If your budget allows, you can go with the 67 marker Y DNA test. But the 37 marker test is also a very good choice, and you can always upgrade to more markers at a later date without submitting a new sample. (And for the truly ambitious, there’s always the Big Y test.)

Follow theYDNA

So what are you waiting for? If you have your own Y DNA, go out and start the testing process. If you have been blessed instead with two X chromosomes, send this article over to your favorite male relative and let him know that he holds a very old, very valuable record in his DNA and you want to help him make use of it.

Learn more about YDNA in our YDNA FREE Get Started Course. Learn the many ways YDNA might help you answer your questions about your family history. The Get Started Course is an excerpt from our YDNA for Genealogy Course, which takes you deeper into understanding Y-haplogroups and using them in genealogy research (as well as other topics such as YDNA matching, surname project participation, and when to use Big Y).

Tell me more about the YDNA FREE Get Started Course!

For guidance through the YDNA testing process, check out my Y Chromosome DNA Quick Reference Guide. It’s an inexpensive yet valuable way to make sure you get the most out of your Y DNA testing investment.

Take me to that Quick Guide!

An older version of this article was originally published at www.genealogygems.com

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<a href="https://www.yourdnaguide.com/author/guideyourdnaguide-com" target="_self">Diahan Southard</a>

Diahan Southard

As founder and CEO of Your DNA Guide, Diahan Southard has been teaching people how to find family history answers in their DNA for several years, and she's been in the genetic genealogy field since its infancy. Diahan teaches internationally, writes for popular magazines, consults with leading testing companies, is author of Your DNA Guide–The Book, and producer of Your DNA Guide–the Academy, an online learning experience.


  1. William


  2. Karen Elsken

    Should I have my father take a YDNA test (he is 87) in case I need it for future reference? He has no sons and is from a long line of only children. At this point I’m not missing any ancestor names so I’m not sure what advantage it would be to have him tested.

    • Danielle Francis

      If it were me, I would definitely have your dad test! DNA is a record unique to him and his ancestors, so I think it is worth saving, especially since it sounds like there aren’t many other people in your family that could take a YDNA test.

  3. Karlene H Ferguson

    FTDNA no longer offers the 67 marker Y DNA test. If someone tests now at the 111 marker, results will show matches at the 67 marker level as well as the lower levels.


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