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Please ignore mtDNA and Y chromosomal haplogroups

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  • Please ignore mtDNA and Y chromosomal haplogroups

    http://blogs.discovermagazine.com/gn...l-haplogroups/


    Is he right? ???

  • #2
    Yes and no. They don't really tell you much about your overall genetic makeup, but they can be useful at tracing particular lineages. He's coming at this from a population genetics approach, not a genealogical one.

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    • #3
      Yes I think he is... if you pay attention to what he's saying. If you go back 10 generations, you have 1024 7th grt grandparents living in the 1700s. Only 2 of those are represented by your mtdna and ydna respectively. So yes he's right in that autosomal dna better reflects your genetic ancestry than does haplogroups. Nevertheless, the mapping of migrations of humans is a story told by mtdna and ydna, so they have their specific use. AND, as we slowly migrate to more complete genome testing, there is the opportunity for subclades to be better and better refined to the point where they do have meaningful genealogical implications.

      I'm currently L193... which puts me in a small group with others of similar Celtic ancestry with a MRCA in the 1500 year range. If a few more snps are discovered, I may eventually belong to a subclade that only has say a few thousand men. At that point, I feel there is significance in the haplotyping. But he's right, don't lose sight that your maternal and paternal lines are INSIGNIFICANT to your complete genetic ancestry, at least in terms of the numbers of ancestors they represent.

      I haven't seen anyone make an argument that despite such insignificance wrt the quantities of ancestors represented, there exists some special significance of ydna and mtdna that makes it genetically more important than the remaining genome. Anyone have an opinion that speaks to this question?

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      • #4
        Originally posted by djknox View Post
        Yes I think he is... if you pay attention to what he's saying. If you go back 10 generations, you have 1024 7th grt grandparents living in the 1700s. Only 2 of those are represented by your mtdna and ydna respectively. So yes he's right in that autosomal dna better reflects your genetic ancestry than does haplogroups. Nevertheless, the mapping of migrations of humans is a story told by mtdna and ydna, so they have their specific use. AND, as we slowly migrate to more complete genome testing, there is the opportunity for subclades to be better and better refined to the point where they do have meaningful genealogical implications.

        I'm currently L193... which puts me in a small group with others of similar Celtic ancestry with a MRCA in the 1500 year range. If a few more snps are discovered, I may eventually belong to a subclade that only has say a few thousand men. At that point, I feel there is significance in the haplotyping. But he's right, don't lose sight that your maternal and paternal lines are INSIGNIFICANT to your complete genetic ancestry, at least in terms of the numbers of ancestors they represent.

        I haven't seen anyone make an argument that despite such insignificance wrt the quantities of ancestors represented, there exists some special significance of ydna and mtdna that makes it genetically more important than the remaining genome. Anyone have an opinion that speaks to this question?

        As has been stated, only Y and Mtdna can be informative about direct male and female lines respectively. My background is Ashkenazi and I have obtained valuable information about the migration paths of my ancestors from Y and Mtdna matches and research focused on my haplogroups. I have over 1800 FF matches but I have no idea as to how they are related to me, all four of my grandparents lived within 40 miles of each other.
        Last edited by josh w.; 20 May 2013, 12:12 PM.

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        • #5
          So I should ignore my Y and Mt results because they tell me a lot about a small number of distant ancestors. Instead I should only bother with autosomal testing so that I can learn very little about a slightly larger number of closer ancestors?

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          • #6
            If you go back 1,000 years, your autosomal DNA has been diluted to the point of irrelevance. But your mitochondrial haplotype is still going strong. It all depends on what you are interested in. I'm not especially looking for living relatives. I'm more interested in my long-range family tree, at least at this point.

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            • #7
              He is wrong.

              He assumes the individual is only looking at their own test results. If so his warning is fair. However If you look at the results of your 2nd, 3rd, 4th, 5th, 6th, 7th, 8th, 16th etc, etc cousins you build up a rich picture of a much wider ancestry.

              Earl.

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              • #8
                Looking at my son for example, he knows his paternal grandfather is R1B (DF27) and his maternal grandfather is I1. His MTDNA heritage is T2 from his paternal grandfather, V from his father, H from his mother (the MTDNA he carries himself) and J from his maternal grandfather.

                More distant 6th and 8th cousins descended from his Brough and Plant ancestors have tested so that information is also known. As more people test more and more of the picture builds. All you need to do is keep an eye on the surname projects for your ancestral surnames the picture will slowly develop.

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                • #9
                  As far as mtDNA testing goes I haven't gotten anything out of it and I doubt that I ever will, but it can be used in certain circumstances to find which of two women was the mother of an ancestress, provided you can find a direct line female descendant to test. I don't thing I'd recommend it to new genealogists.

                  The Y-DNA test I would recommend considering the number of people who have discovered non-paternity events this way. There is no use spending years researching the wrong line if you can avoid it. Been there, done that. But in my case, it took me about 5 years to persuade a cousin to do the test.

                  It's surprising how often you read about Y-DNA tests turning up unexpected non-paternity events.

                  These tests can also be used to prove or disprove rumors and family traditions about adoptions, etc. So, in my opinion, they do have their usefulness with regard to recent genealogy. You just have to know what each test does. And it appears that a lot of people who purchase them don't have a clue!

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                  • #10
                    The problem is, many people are getting autosomal testing, and then are only wanting to follow or contact others who have the same y or mt DNA. Completely missing the point of the autosomal testing---that it can connect you with cousins and relatives from many other branches of your family than just the direct y or mt lines. I tried to explain this to our computer genealogy group recently, some of whom have done some DNA testing. Since the y and mt testing came first, many people have it ingrained in their brains that they can ONLY find ancestor connections by following the y and mt DNA. One woman insisted over and over that she wanted to know why she couldn't get her father's yDNA from her testing. It didn't matter that we told her that she did not have a y chromosome to test. BUT that autosomal testing would show the half of her DNA that came from her father.

                    This is getting to be a big problem, where some people refuse to reply to queries about shared ancestry because "we don't share the same y or mt DNA", when they do share a good piece of atDNA, and are probably close cousins.

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                    • #11
                      I tend to find autosomal DNA evidence to give me the best overall picture of my ancestry. (My first Family finder results brought up the ancestral name of my 2x great-grandmother and I repeatedly get many matches associated with her extended family, as does my mother.)

                      My Y DNA haplogroup points towards a Jewish male ancestor -- my great grandfather was supposed to be Jewish -- but I receive few Ashkenazi matches (my father receives slightly more than me and he fares better on the J-test on GEDmatch). My direct maternal line was German, but most of my mt DNA matches appear to have little to do with Germany (except for my one exact match who has never replied to a message). My mt matches' largest percentages point towards people in Greece, Slovenia, etc. and I believe my mt haplogroup originated in that general area. In some respects, for me anyway, mt DNA is more important in determining possible migration routes of ancient ancestors that it is in determining recent ancestry. Still, I have to admit (for what it's worth) my great-grandmother, a child of German immigrants, looked very little like other German people I have associated with in my life (I am from the Midwest).
                      Last edited by mixedkid; 22 May 2013, 01:28 AM.

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                      • #12
                        Originally posted by gatty View Post
                        Nope. I think he is wrong. People can find meaning in getting a certain haplogroup especially if it is a rare haplogroup. Look at how he was addressed in the comments on that issue of say a person who get 100% European on autosomal, but gets the Native American haplogroup. That speaks volumes. His answer to that also rests this issue for me.

                        Sorry people I think it is sad how quick people can be to discount the direct maternal and paternal lines as if they are meaningless. These, as PDHOTLEN pointed out are not going to recombine or mutate so fast, so in most cases you have a clear picture. Actually a big turn off for me has been reading the folks on the 23&me forums bash the yDNA and mtDNA tests as if they are useless. Wow, even with the autosomal you are not getting 100% of all of your ancestors. And I do look at my Family Finder cousins that have done Y or Mito testing and ponder if it can be significant part of my ancestry. I have some lines that I will never be able to test for Y or Mito or autosomal for sure because they are a brick wall. This would be the case of my father's father's mother. So unless I can learn more if she had a sister with descendants then there is no one to test from that line.

                        Anyway I think all tests have useful meaning in them. Even my having mtDNA H, even just knowing it is H (and a ridiculously bushy branch) told me that I needed to continue looking for my direct maternal line in Europe not America.

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                        • #13
                          Originally posted by R Walker View Post
                          The problem is, many people are getting autosomal testing, and then are only wanting to follow or contact others who have the same y or mt DNA.
                          Really? There are many people doing something so obviously stupid? I'd really not noticed.

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                          • #14
                            With me, I can put my maternal ancestry into separate blocks. The colonial block has been the most rewarding, since it has been easier to trace. My Austrian block quickly is a dead end. Then there is a "Pennsylvania Dutch" blocklet that also comes to a brick wall. And a segment that goes back to the Pensylvania area that is separate from the PA Dutch segment, and includes connections to that old Swedish colony, with some Dutch (and apparently Welsh) in there. Then there is the Falconbury threads that go back to New Jersey in the 1600s, with a connecting thread that is a mystery (NC). Those are all family tree lines and segments. And all of the above is on my maternal side. But how to connect all the Family Finder matches to those segments is a problem.
                            Last edited by PDHOTLEN; 22 May 2013, 08:39 PM.

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                            • #15
                              Originally posted by Earl Davis View Post
                              Looking at my son for example, he knows his paternal grandfather is R1B (DF27) and his maternal grandfather is I1. His MTDNA heritage is T2 from his paternal grandfather, V from his father, H from his mother (the MTDNA he carries himself) and J from his maternal grandfather.

                              More distant 6th and 8th cousins descended from his Brough and Plant ancestors have tested so that information is also known. As more people test more and more of the picture builds. All you need to do is keep an eye on the surname projects for your ancestral surnames the picture will slowly develop.
                              Earl - you're right but the logic is self defeating in the sense that one cannot access the mtdna or ydna of their ancestors past a couple of generations. So regardless, the vast majority of your son's ancestors are completely ignored by mtdna and ydna testing. So ultimately, only the maternal and paternal lines of the tested can be studied. AND, most of us doing this don't have grandparents to test.

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