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.

21 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. This is why I haven’t done a DNA test, some of these outfits sell your information. (yes they do)

    2. 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 genealogy.com
      Do I have to do genealogy.com to connect my kids to me?

    2. If I test with Ancestry, is my DNA also matched with 23 and Me or any other DNA test centers? Or what about family search

      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 Geni.com), 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

      1. Dear Gena,

        Thank you so much for your detailed reply above. I just read about Family Finder testing from that FamilyTree DNA testing outfit in Texas, from which I have had at least 3 different tests taken, for tracing and proving the existence of my ancestors. The 3rd test I took was their autosomal, or Family Finder test, which does both sides of one’s family. I did not know how far-reaching that test was, since my 2 previous tests were my dad’s direct line, his surname of MacGregor, for the American Clan Gregor Society, the Scottish hereditary chief, Sir Malcolm MacGregor of MacGregor, retired British Army major, as the real head of the MacGregor clan. I have also read that DNA testing is only 3% of your ancestral make-up, or whatever the 3% really means. I never liked the contacts from other people, unknown to me, and maybe not even Americans or Canadians, so I never replied to them. My Mayflower ancestry is on my mother’s side, not my dad’s side. However, I never got any replies or inquiries from close or very distant cousins, replying to me directly about my mother’s ancestry.

        I have read just now, also, that full-blooded siblings of yours may differ in the traits that you have inherited from the same ancestors, so it is well to take several different tests from different companies, because one’s sibling might have inherited a trait, such as red hair, from one of the ancestors, which ancestor whose red hair you didn’t inherit! I hope I am explaining this properly. I have twin grandsons, for instance, but they are fraternal twins, not identical twins, so each twin inherited, looks wise, facial characteristics that were different from his twin brother.

        Therefore, if I never heard from any of my mother’s ancestors’ cousins or their descendants, who had their DNA done, I wouldn’t have to panic. I have a feeling that I had a different code number for myself in the autosomal test, different from the Y-chromosome male, MacGregor, testing, so somehow FamilyTree DNA testing in Texas loused it up. I always thought it was odd that I never heard from any non-MacGregor distant cousins, after I took the autosomal test, but I wanted to have anyone who looked up my autosomal test to look up also my first cousin (male, now deceased’s) Y-chromosome DNA MacGregor tests, 12 or something number higher and the 67 Y-chromosome test. I wanted to find out exactly where in Perthshire, Scotland, my great-gf came from to Nova Scotia in 1832, but I never really found out. My dad and his dad and aunts and uncles said my gf came from Loch Rannoch, Perthshire, Scotland, and I have been there twice, but I never really found out exactly. I did meet the last MacGregor, a Janet MacGregor, who lived in Kinloch Rannoch the last time I was there, circa 1995, plus or minus, and I met her brother and sister there in 1960, but I really couldn’t find solid dirt proof! Grin.

        Now, I need a document, terribly elusive, government or church document, to prove that my Mayflower ancestor, Matilda Pineo, born 1822 in Cornwallis, NS, to John Pineo and Sarah (Ells) Pineo, actually was the daughter of John Pineo and granddaughter of Rev. John Pineo and Hannah Loomer. Canadian records were so often non-existent, and non-required, though she appeared as an old lady, or the grandmother (not her ID specified!) and without her by then deceased parents listed, in the Canadian 1871, 1881, and 1891 censuses for Cornwallis Township, Kings Co., Nova Scotia. Please reply here to me and also to me directly at Rjmsimon@knology.net, because I won’t know when you reply here, or I might never find it again. Thanks so much. Rosamond Jean (MacGregor) Simon, Huntsville, Alabama, Deputy Area Chieftain, American Clan Gregor Society 13 Sept 2020

  4. Thank you! The information about different DNA tests answered a question I’ve had for years, perhaps preventing me from going ahead with having it done. Good thing I waited. I suppose I could have done enough research to find the answer for myself, but you have presented it clearly. I trust GenealogyBank as a source.

  5. I did a test with 23andMe. Do you have the results from that or should I do it again?

  6. I recently did a 111-STR test expecting to get some surname matches. None, on ftDNA.com, 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.

  7. 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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