Have you been wondering what’s up with the Y? After taking an autosomal DNA test, many genealogists want to know what next steps to take, and if YDNA can help further their research. YDNA, which can only be taken by males, may be able to bust additional brick walls in your family. DNA expert Diahan Southard is here to share 3 reasons to take a YDNA test–or have a male relative do so.

The Y chromosome DNA test, more affectionately referred to as the YDNA 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. Currently, the YDNA test is available at Family Tree DNA. Here’s their quick recap of what YDNA is:

“Y-DNA is what we call the sex chromosome “Y” that is passed from a father to his sons only, women do not receive a Y chromosome. Testing the Y chromosome allows for investigation into a male’s paternal family line and can help identify surname lines, living relatives whose Y chromosome is similar to yours, and ancient migration routes your paternal ancestors may have taken.”

At Family Tree DNA, there are four levels of YDNA testing available. 37 markers is the base level and a good place to start making connections. You can also increase your marker count to 67, 111, or if you’re a DNA expert, you can opt for the whopping 700 marker test. The good news is that you can start with the 37 marker test and have the option to upgrade to the larger test without needing to provide another sample.

YDNA has several excellent qualities that make it useful in many genealogical scenarios. Let’s look at three to give you a good start!

Use YDNA for Genealogy When…

1. You Have a Missing Father

All of us should be able to identify with this genealogical problem. Every line in your family history has this problem. Any ancestor whose father is currently unknown falls in this category. And YDNA can help.

The specific quality of YDNA 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 man to the next. That means that any living male today has the same (or very similar) YDNA as every male in his direct paternal line, back 8, 10, 12+ generations.

Therefore every man’s YDNA is the clue that could lead you to discover that missing father. Usually what it takes is a match in the YDNA 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.

2. Your Relative is Worried About Privacy

While DNA testing has certainly entered a season of relative acceptance among genealogists, there are still many skeptics who wonder what the eventual ramifications of having your DNA tested might bring. While this is a subject that certainly deserves some attention, the YDNA 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 YDNA, make it equally impossible to identify any particular individual uniquely. This means that the YDNA record that is created when a man takes a YDNA test cannot ever be traced back to him alone. That same record could have easily come from his brother, or 1st, or 5th cousin.

Similarly, the YDNA test results do not have a 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.

3. You Have a Surname Mix-up

One of the best applications of YDNA for genealogy 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 YDNA 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, YDNA 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.

So what are you waiting for? If you have your own YDNA, 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 DNA Test Options in This Free Video Class

Learn more about YDNA testing and the other types of DNA tests in this free video class, filmed live at RootsTech 2018! You’ll get answers to questions like:

  • Which DNA test should I take?
  • What will I get from the DNA test results?
  • Will DNA testing help with genealogy?

If you or the relative you want to test wants more information about what DNA testing is all about, this is the perfect recap. And best of all, it includes helpful slides, graphics, and it’s all in plain English!

About the Author: Diahan Southard has worked with the Sorenson Molecular Genealogy Foundation, and has been in the genetic genealogy industry since it has been an industry. She holds a degree in Microbiology and her creative side helps her break the science up into delicious bite-sized pieces for you. She’s the author of a full series of DNA guides for genealogists.

Disclosure: This article contains affiliate links and Genealogy Gems will be compensated if you make a purchase after clicking on these links (at no additional cost to you). Thank you for supporting Genealogy Gems!

This article was originally published on April 27, 2016 and updated on May 2, 2019. 

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