Genealogy 101: Two Questions to Ask before DNA Testing

Introduction: In this article – part of an ongoing “Introduction to Genealogy” series – Gena Philibert-Ortega provides good advice to consider before doing a DNA test. Gena is a genealogist and author of the book “From the Family Kitchen.”

Chances are, you’ve joined most genealogists by testing yourself or a loved one’s DNA. There are a lot of reasons for taking a DNA test. But if you haven’t yet tested yourself, or are getting ready to ask a family member to test, stop and consider these two questions: why am I testing and which DNA test should I take?

Illustration: the most common Y-DNA-haplogroup in different regions in Europe
Illustration: the most common Y-DNA-haplogroup in different regions in Europe. Credit: Robert Gabel; Wikimedia Commons.

Why Am I Testing?

Are you curious about where your ancestors came from? Want to confirm or disprove a rumor about your ethnic origins? Maybe you’re searching for your birth family or you’ve recently learned that the father who raised you isn’t your birth father. Reasons for taking a DNA test include:

  • Solving a brick wall
  • Finding answers for an adoptee or someone of unknown heritage
  • Ethnicity estimates
  • Finding information about your most recent common ancestor
  • Identifying cousins
  • Determining the relationship between two or more people

An individual’s reasons for taking a DNA test range from pure curiosity to getting answers to specific questions. Asking yourself why you are taking the test will help you decide what test and which company you should test with.

What if you’re asking someone else to take the DNA test? It’s important that when you ask someone to test, you take the time to answer their questions and give them all the information they need in order to make an informed decision. Likely they have heard about DNA testing and may have some concerns based on what they have heard. Make sure to be clear about:

  • Why you are asking them to take a DNA test. (What are you trying to learn? What question will it answer?)
  • What type of information could be revealed by a DNA test.
  • What DNA testing company you will be using.
  • What they will be required to do.
  • Who will have access to their information (discuss privacy options and how they can access their information).
  • What additional websites you may be uploading the information to.

You don’t need to be an expert in genetic genealogy to answer their questions, but you’ll want to do your homework. You may want to consult online resources from genetic genealogists and the International Society of Genetic Genealogy (ISOGG) Wiki. The ISOGG Wiki Beginners’ Guides to Genetic Genealogy is very helpful in learning more about genetic genealogy.

Remember: this is their sample – they have the right to control what they provide and what is done with it.

Which DNA Test Should I Take?

Now that you know what question you hope to get answered by a DNA test, you can decide on which test you should purchase. Keep in mind: you may not be able to provide a DNA sample that answers your question. For example, if you are a woman wanting to trace a male line using a Y-DNA test, you can’t provide that sample. You’ll need to find a male relative.

The three types of tests you’ll want to be familiar with are:

  • Autosomal: This test provides results from both sides of your family. It’s a great way to get a sense of your overall background and to receive matches for cousins that are related to you through your paternal and maternal lines. An autosomal test provides a look at all the possible branches of your family for about six generations. However, this test will only reveal what you’ve inherited, so it won’t be your family’s complete genetic makeup. One reason people test all of their siblings is because each person can inherit different DNA. What you didn’t inherit from your ancestors your sibling might have, and vice versa.
  • Mitochondrial (mtDNA): This DNA test provides results from your direct maternal line. The mitochondrial is passed down from a mother unchanged to her children, both male and female. This test looks at your ancestors, thousands of generations back in time.
  • Y-DNA: This test, taken by males, traces their paternal line (father>father’s father, etc.). Just as in the case of the mtDNA, this test can look at your genetic genealogy thousands of generations back in time.

DNA testing companies may offer one or all of the above testing kits. You may want to explore companies and what they offer prior to buying a DNA kit. You can find more information on the ISOGG Wiki.

Have You Taken the Test?

DNA is an importation addition to the tools available to family historians. However, it’s important to identify the question you hope to answer and which test can help you answer that question. DNA testing does not mean you will always have an immediate answer to your question. You may have to wait for the right person to test in order to get the match you need. It also does not replace good genealogical research – but when used in conjunction with genealogical research, DNA can help you find answers when a paper trail goes cold.

16 thoughts on “Genealogy 101: Two Questions to Ask before DNA Testing

  1. I have had my DNA tested, and as a result, I frequently get emails proclaiming “You have a match.” Typically, the match is less than 1%, and the individual, whom I never heard of before, is identified as a possible 3rd cousin, once removed, or something like that. How likely is it that the match is real and not just noise?

    1. George, you would need to look at the person’s tree vs your own tree and see who the common ancestor is. A 3rd cousin should share a set of 2nd great-grandparents with you. Now the problem is whether the other person knows their family history going that far back and whether they have a tree you can take a look at.

  2. Another important question to ask is: “Are you prepared to discover (or be discovered by) previously unknown relatives?” I think most people don’t understand the concept of matching, especially those who test just to discover their ethnicities.

    1. Absolutely Susan! It’s important to remember that DNA results can open up closets that you or your family are not prepared for. That’s why if you ask someone to take a DNA test, you need to make sure that they understand what could happen as a result of that test. Thanks so much for your comment.

    1. I wonder about this too. My cousins and I did 23 and me. My x wife did
      Do I have to do to connect my kids to me?

      1. John, no. Your Ancestry DNA test is matched with others who have taken the test on Ancestry. If you are interested in another DNA testing website you would need to either take their test or look into adding your results. FamilySearch does not provide DNA testing. Thank you for your question.–Gena

  3. Is there yet a DNA test that will help me confirm or prove that my Nova Scotia-born maternal grandfather’s maternal grandmother is the daughter of her father (John “Jack” Pineo born 30 June 1785 in Cornwallis, NS, a Mayflower descendant)? I need it to strengthen my application for membership to the Mayflower Society. This lady, born 17 April 1822 in Cornwallis, Matilda Pineo, is my weakest link, because I cannot find credible primary records (not the likes of, or church records, that she is the daughter of her father, John “Jack” Pineo.

    I have done 3 successive Y chromosome tests with Family Tree on my direct male line. I am female. That was no help for my Pineo ancestors.

    1. Rosamond, this is a great question that I probably don’t have the best answer for since genetic genealogy is not my specialty. I would think it would be important for your to test with a company that has a sample population from Nova Scotia. If you were to take an autosomal test that would help you reveal matches on both sides of your family but you may not carry any DNA or very little from that ancestor. The other issue is, if no one has tested who is related to that ancestor than you won’t get any matches. That’s why genetic genealogists recommend taking multiple tests with multiple companies. Sometimes the right match is simply a waiting game for the right person to test. I would recommend that you contact either a genetic genealogist or one of the DNA testing companies for some guidance regarding the appropriate steps to take. Good luck!–Gena

  4. I recently did a 111-STR test expecting to get some surname matches. None, on, despite being in the RM-269 predicted haplogroup common to 3/4ths of Euro men.

    Is it true that the only way a Y-DNA test will identify 3, 4, or even 10 generation ancestors is to test other possible descendants of those same ancestors to compare exact SNP and STR values?

    If that’s true, then expectations are oversold. The comeback I’ve seen from projects admins to folks who had no surname matches has been: “you need more tests! You need to find more people to test!”

    Do they get a kickback??

    I’ve tentatively concluded that general DNA projects (not specific to a surname) are primarily interested in genetic anthropology, not genealogy. The Key Performance Indicator would appear to be increasing the number of haplogroup branches… and selling tests.

    Unless someone convinces me otherwise, I will advise any male who asks to not waste their money.

    1. Paul, DNA testing/matching is all about waiting for the right person that has tested with the company you have tested with. That’s why genetic genealogists recommend multiple tests for multiple testing places. It’s like a bread crumb trail…you are leaving information out there waiting for someone to match and then taking a look at their genealogy and yours to see who the common ancestor is. Yes, there’s the possibility that might not happen for a long time.

      I think it’s fair to say that many of those who take DNA tests are interested in their ethnicity results and nothing more. Everyone takes a DNA test for their own reasons and that’s definitely not always about genealogy.

  5. I suspect there’s fraud in some DNA findings. I cannot quibble with what I received, but my aunt in Michigan (related by marriage only) had hers done and after a delay or two in the past year+, she received her results. Shockingly, hers and mine were near identical, and she did not have the same bloodline with me. Because we have the same family name, I suspect the results were manipulated so they would be near identical.

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