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The Importance of Y-DNA Testing (It's NOT Like Astrology!)

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  • The Importance of Y-DNA Testing (It's NOT Like Astrology!)

    Read the Guardian article at the link posted below, but here are my comments on it. Mark Thomas is technically correct but, overall, and in very important ways, he is wrong. He is especially wrong to compare the deep ancestry aspect of genetic genealogy to astrology. By far most of us understand what y-dna and mtDNA testing represent: gaining information on just two of the many ancestral lines that have gone into making us who we are genetically. Yes, all those things Thomas wrote about our ancestry in the aggregate are correct. We have many ancestors, and all of us humans share ancestors. But that does not diminish the importance of our y-dna and mtDNA lines, which give us bread crumb trails that we can follow into the past. Amidst the welter of genetic confusion, of combination and recombination, of cell division and mutation, at least we have two paths we can follow that offer us some clarity. At least we are able to say something about our ancestors beyond statistical probabilities at the population level. And not only that: y-dna and mtDNA are our keys to be able to say something definite about some of our other lines, as well. Each of our ancestors, whether they were in our direct y-dna or mtDNA lines or not, had y-dna and mtDNA lines of their own. When we can find relatives on those collateral lines who stand in the y-dna or mtDNA lines of those ancestors, they can be tested to reveal information about them and thus give us more bread crumb trails we can follow into the past.

    For example, although I am a Stevens and am R-DF41 on my y-dna line, I know through distant cousins who have also had y-dna testing that one of my 3rd great grandfathers, Abner Standish Washburn, belonged to y haplogroup I1 (I-M253). I also know, through another set of distant cousins, that one of my 2nd great grandfathers, John Holmes, was E1b1b (E-M215). So, now I know of not one but three y-dna bread crumb trails into the past that I can explore. I got my father's dna sample into Family Tree DNA's system via a 12-marker y-dna test that was on sale a few months ago (he matches me exactly, of course). As soon as I can get his sample tested for mtDNA, I will have yet another genetic bread crumb trail to follow.

    My Family Tree DNA Family Finder test results, while themselves autosomal, are also revealing more and more y-dna and mtDNA bread crumb trails as they connect me with relatives who stand in the same y-dna and mtDNA lines as some of my ancestors. For example, one of my 2nd great grandmothers was a Stewart. I have several Family Finder matches with Stewarts and persons with Stewart in their list of surnames. It certainly looks like my 2nd great grandmother's Stewart line is the source of those matches. These Stewarts happen to be some of those in the "Royal House of Stewart" line, the same one that produced a number of famous kings and queens of Scotland and England. That Stewart y-dna line is DF41+, like my own y-dna line, and L745+, as well. There is yet another y-dna trail to follow into the past.

    So, with all due respect, Mark Thomas is wrong.

    http://www.guardian.co.uk/science/bl...tors-astrology

  • #2
    I was hoping

    Thanks for your excellent rebuttal. I was hoping someone would come back with a good rebuttal with evidence of their own dna testing to prove that he was wrong in what he said. I am an adoptee with no papertrail, but despite that, I know my ydna, mtdna and autosomal test results are accurate, and I believe I do have Scandinavian ancestors, and probably Viking ancestors as well on my paternal side.

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    • #3
      Yes, Stevo. In the case of Y-DNA and mtDNA, there is also the sentimental value of knowing that these vast DNA segments -- present in every cell of our bodies -- have been passed down to us in an unbroken chain by our patrilineal and matrilineal ancestors for thousands of years. (In my case, just mtDNA, since I am female.) I find this to be unspeakably cool.

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      • #4
        Originally posted by Everwaiting View Post
        Yes, Stevo. In the case of Y-DNA and mtDNA, there is also the sentimental value of knowing that these vast DNA segments -- present in every cell of our bodies -- have been passed down to us in an unbroken chain by our patrilineal and matrilineal ancestors for thousands of years. (In my case, just mtDNA, since I am female.) I find this to be unspeakably cool.
        If your post was on Facebook, I would have hit the "Like" button. Here I can just give you a thumbs up thingy at the top of this post and a smiley here.

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        • #5
          Originally posted by Mylineage View Post
          Thanks for your excellent rebuttal. I was hoping someone would come back with a good rebuttal with evidence of their own dna testing to prove that he was wrong in what he said. I am an adoptee with no papertrail, but despite that, I know my ydna, mtdna and autosomal test results are accurate, and I believe I do have Scandinavian ancestors, and probably Viking ancestors as well on my paternal side.
          Thank you very much. I am glad you are with us in the great brotherhood and sisterhood of dna testing.

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          • #6
            Stevo,

            I believe you match my mother and myself on the FF test, and before the upgrade to Build 37, you also matched my cousin.

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            • #7
              I think the key is in following those "bread crumbs". A haplogroup or subclade could point to a certain group of people at a certain point in time or even a geographical location but e.g. to claim Viking ancestry based on a haplogroup alone is indeed as speculative as astrology. You either need convincing matches or a good paper trail.

              A good example is Eddie Izzard meeting his English "Saxon" match. He greeted his match saying; "we seem to be Saxon cousins", with the other man saying; "I thought we were Viking?" And they both could be right, they could be of Saxon ancestry but they also could be of Viking ancestry.

              I think Mark Thomas points out that putting such a label on a haplogroup or ancestry is scientifically incorrect and I agree with him. For instance; someone in Britain with haplogroup I1 could have a Viking ancestor, but also could have a Saxon ancestor, he might even have a Roman ancestor, or his ancestor could have moved to Britain in the high middle ages. You just can't say for sure without alot of matches or a paper trail.

              It doesn't mean genetic genealogy isn't interesting, of course it is, and afterall it is a work in progress.

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              • #8
                Yes, but Mark Thomas did not stop with criticizing wild historical or tribal claims. He actually belittled the worth of y-dna and mtDNA testing for genealogical purposes. That is what I object to. Thomas made it sound as if we all are a bunch of rubes being duped by unscrupulous dna testing companies. I object to that characterization, as well.

                The difficulty in distinguishing Anglo-Saxon from Viking ancestry is well known and not the same thing as claiming that even getting in that ballpark is just impossible or unrealistic. After all, the Anglo-Saxons and Vikings were much the same people, separated by a few generations and the civilizing effects of conversion to Christianity in the case of the former. Trying to figure out whether one's y-dna line contained a Viking or an Anglo-Saxon is a fairly pleasant dilemma and beats the heck out of not having a clue.

                I didn't have much of a clue before I got into genetic genealogy. Now I know a lot more than I did and am pretty confident about where my immigrant y-dna ancestor came from. I am even pretty confident that my more distant y-dna ancestors included British Isles Celts. I can't name the tribe - not yet - but who knows what the future holds?
                Last edited by Stevo; 3 March 2013, 04:02 PM.

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                • #9
                  Originally posted by MoberlyDrake View Post
                  Stevo,

                  I believe you match my mother and myself on the FF test, and before the upgrade to Build 37, you also matched my cousin.
                  Hi! And thanks for the email!

                  I have high hopes that we will be able to make some sort of breakthrough.

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                  • #10
                    it is like astrology

                    thanks for sharing the article.

                    yes we have two paths (breadcrumbs) to follow as stevo (op) mentions but that is irrelevant in the context of the article which compares claims like "i am from XYZ origin" to genetic astrology. Indeed, I cannot agree more.

                    The only thing that is missing, also in the comments by stevo, is an estimate of the number of unique ancestors as a function of number of generations back in time. In the Viking time, ca 40 generations ago, well you cannot have 2^40 ancestors. I would assume that after 20-25 generations ago there must be a significant number of duplicated ancestors and probably the number of ancestors starts to decrease again in line with the decrease of the world or regional population at the time. Otherwise indeed we would all guaranteed have viking, roman, aboriginal and indian origins. But we don't because in reality we didn't have that many ancestors to cover all these ethnic groups. That's missing from the article and the comments. However, ydna or mtdna would still be largely irrelevant as it covers only 2 or a handfull of ancestral lines.

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                    • #11
                      Originally posted by lc0 View Post
                      thanks for sharing the article.

                      yes we have two paths (breadcrumbs) to follow as stevo (op) mentions but that is irrelevant in the context of the article which compares claims like "i am from XYZ origin" to genetic astrology. Indeed, I cannot agree more
                      . . .
                      Good for you, but it is not irrelevant given the context of the article, in which Mark Thomas criticizes the use of y-dna for genealogical and deep ancestry purposes. Had he stopped at a criticism of extravagant claims, I would not have had anything to say, but he did not stop there. Instead, he went on to a sweeping criticism of the use of y-dna for anything beyond population studies by experts.

                      The astrology analogy is ludicrous. Astrology is not based on science, but even extravagantly speculative y-dna claims are based on science, especially on the modern distribution of y-dna haplogroups. A claim of Viking ancestry for someone of British ancestry who belongs to a y haplogroup common in Scandinavia may be excessive and perhaps inaccurate, but at least it has a basis in fact. Some of those claims may in fact be accurate, when supported by sufficient evidence, such as str matches, membership in a geographic cluster common in Scandinavia, SNP test results, etc.

                      Mark Thomas also belittled y-dna testing by noting that it "only" accounts for a single line of descent. As I pointed out, he neglected the practice of networking with relatives as a means of uncovering multiple y-dna and mtDNA lines.

                      Besides, even though it only accounts for a single line, for me my y-dna line is extremely important. It connects me to my father, and to his father and his father, on and on into the dim past. There is a spiritual as well as a biological connection there. I think most men instinctively know or feel what I am talking about. No doubt many women do, as well. No offense to all of my other forebears, but for me my y-dna line is supreme. Finding my y-dna immigrant ancestor is the Holy Grail of my genealogical quest.
                      Last edited by Stevo; 9 March 2013, 07:45 PM.

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                      • #12
                        Well said Stevo

                        Stevo,

                        Like you my ydna testing along with snp testing is my Holy Grail, especially being that I am an adoptee with no paper trail. I have been at this for (4) years, and I have successfully tracked my paternal lineage to a specific surname/family line, and I am in the last stage, which is probably the hardest, that being, finding the correct branch back to me. I have had more success with paternal testing then maternal or autosomal, but agree it is all important to complete the whole dna puzzle.

                        Douglas W. Fisher-Kit#122883
                        R1b-U106+Z18+Z14+Z372+ (L257 test is in progress)

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