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Rethinking Non-Surname Matches

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  • Rethinking Non-Surname Matches

    I’d like to suggest that it’s time rethink our approach of dismissing matches with other surnames. I’m suggesting this for 2 reasons. (1) the extension of testing to 37 and 59 markers brings the MRCA time horizon much closer and consistent with the use of surnames (last 500 years) and (2) the rate of non-paternity events is much higher and much more probable than first realized.

    For example, if one reads the FTDNA position on non-surname matches,
    http://www.familytreedna.com/trs_explain.html the basic argument is that there is too little data (too few markers) to dismiss paper genealogies. For example, in the extreme case of 1 marker, huge segments of the population match and DNA testing doesn’t really tell us anything.

    Specifically, the FTDNA site states:

    “If you compare the 12 marker result to someone else who does not have the same surname, but the scores match, you are most likely NOT recently related. When we use the term recently related, we are talking about a time frame within the last 1000 years or 40 generations, a time depth that accommodates the earliest known use of surnames.”

    It also should be noted that this page was written when 12 marker testing was common and 25 markers was state-of the-art. A 12/12 match had a 90% probability of a MRCA of 24 generations (840 years) which is at the cusp of when surnames were becoming popular.

    The page goes on to state that for a small number of markers, “the importance of a surname link is paramount to provide a comfortable conclusion of relatedness. Most of the time random matches with people with different surnames do not stand the test for extended DNA testing.”

    However, as the number of markers increases, this argument no longer holds water. As the number of markers increases, the fidelity of the analysis will approach CODIS and forensic analysis and high resolution non-surname matches will become as relevant as surname matches are today.

    For example, the table below shows the MRCA of perfect matches at a 90% confidence level. Clearly 12 markers can do no better that take us to the time when surnames were being created, and 25 markers don’t even bring us to the time when most people’s paper trails hit a brick wall. (From my experience, most paper trails hit brick walls in the 1700s.)

    90% likelihood of MRCA
    12/12 24 generations 840 years “almost beyond surnames”
    25/25 10 generations 350 years “beyond most brick walls”
    37/37 5 generations 175 years “within paper trails”
    59/59 ? generations <100 years “within paper trails”

    I think that most people would agree that in the future when 100 and 150 marker tests are common, we will need to look closely at all matches, not only those within a surname. However, in looking at this table, it should be noted that 37 and 59 marker tests bring us well within the timeframe of paper genealogy.

    So, when high resolution 37 and 59 marker tests conflict with paper documentation – what gives? I believe that one aspect of matching that we tend to ignore is non-paternity events. The occurrence rate of NPE’s is much greater than generally acknowledged and frequently ignored by genetic genealogical analysts.

    My proposition is that not only as the number of markers increases, the importance of matches across surnames becomes much more relevant, but that 37 and 59 marker testing brings us to this point today.

  • #2
    Brick wall customers

    I probably look at this question differently than many since my great-grandfather was abandoned as an infant and I don't know who his birth father was. So my initial and main motivation for getting involved in genetic genealogy was to knock down a brick wall.

    Anyone like myself with a brick wall to knock down has to view any perfect or near perfect match at 37 markers as highly significant. I don't know the surname of my gg-grandfather, so it doesn't matter to me what's the surname of the person with whom I match. As long as they had Sicilian ancestors in the last couple of hundred years, that match would be highly significant to me.

    That's why I think geographic projects are very important. I'm sure there will be many cases of people finding matches with others in the same geographic project, even without matching surnames, as more people test and join geographic projects.

    Mike Maddi

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    • #3
      I don't think it is necessary to assume a high rate of female infidelity. There are many reasons for non-surname matches. The case of Mike's great-grandfather is a prime example. Another quite common one, I'm sure, was the death of both parents and the parceling out of siblings to different if often related families. If the siblings took different surnames and failed to preserve - or perhaps did not even have - the memory of who their parents were, that could result in non-surname matches.

      Comment


      • #4
        The other obvious reason for paying attention to other-surname matches is that in some places in Europe, surnames did not stabilize until serfdom was abolished around 1850.

        Outside of Europe, surnames may not have stabilized until even later.

        Comment


        • #5
          Hope for the near future

          Excellent point about the higher level marker tests. After all we see people with 200 -12 on 12 matches, with only their relatives represented at the 37 marker level.

          Certainly there are not enough 37 marker tests out there yet for any hard rules. In the next couple of years it will not be uncommon for different surnames to cluster around close 37 or 59 marker values. That is what the geographical projects are hoping for.

          I often think about where we will be in 5 years.

          The project I am in has over 30 unique, haplotypes for my surname out of 100 participants. The other 70 cluster around several well established old genealogies. I would imagine many of you reading this see the same in your projects unless you have an unusual surname.

          I have been able to trace my family back to Derbyshire in England. What I have discovered is that the neighboring counties of Cheshire and Lancashire had over a thousand in each county in the early 1800s.

          Now, I am pretty convinced that these neighboring counties don't represent the same genetic line. Evidence for this is slowly trickling in. So...while I may have the right place, I can't be sure because my surname is too common. But...If other families start to match a few markers off at 37 and 59, AND come from the same areas then BINGO.

          Not to mention that those people who are looking further back in time like the E3B project will get better results with samples at the higher marker level. The picture will go from fuzzy to sharp focus. Then these groups could be further tested as candidates for discovering new SNPs.

          Don't you just sit there wondering.... If these 12 marker hits only upgraded to 37 what would I discover!

          Comment


          • #6
            Originally posted by EBurgess
            Excellent point about the higher level marker tests. After all we see people with 200 -12 on 12 matches, with only their relatives represented at the 37 marker level.

            Certainly there are not enough 37 marker tests out there yet for any hard rules. In the next couple of years it will not be uncommon for different surnames to cluster around close 37 or 59 marker values. That is what the geographical projects are hoping for.

            I often think about where we will be in 5 years.

            The project I am in has over 30 unique, haplotypes for my surname out of 100 participants. The other 70 cluster around several well established old genealogies. I would imagine many of you reading this see the same in your projects unless you have an unusual surname.

            I have been able to trace my family back to Derbyshire in England. What I have discovered is that the neighboring counties of Cheshire and Lancashire had over a thousand in each county in the early 1800s.

            Now, I am pretty convinced that these neighboring counties don't represent the same genetic line. Evidence for this is slowly trickling in. So...while I may have the right place, I can't be sure because my surname is too common. But...If other families start to match a few markers off at 37 and 59, AND come from the same areas then BINGO.

            Not to mention that those people who are looking further back in time like the E3B project will get better results with samples at the higher marker level. The picture will go from fuzzy to sharp focus. Then these groups could be further tested as candidates for discovering new SNPs.

            Don't you just sit there wondering.... If these 12 marker hits only upgraded to 37 what would I discover!

            lol look we are at 100,000 people but thats a drop in the bucket wait til its 90,000,000. then you ll see what things really mean

            this is just the start

            Comment


            • #7
              Brick Walls

              Originally posted by MMaddi
              Anyone like myself with a brick wall to knock down has to view any perfect or near perfect match at 37 markers as highly significant. I don't know the surname of my gg-grandfather, so it doesn't matter to me what's the surname of the person with whom I match...

              That's why I think geographic projects are very important. I'm sure there will be many cases of people finding matches with others in the same geographic project, even without matching surnames, as more people test and join geographic projects.
              I can relate to this point...

              My grandfather was born with a surname given by his mother that was not even the surname of the alleged father.

              Then, in his teens, GF changed his surname to yet another...

              No one in the family knew about that or aren't talking.

              I do have clues to his real father's name, so I've joined that surname project as a way to break that brick wall.

              Comment


              • #8
                Non-surname match need to be seriously consider

                Here is what I know as a genealogist who's been at this for over 12 years:

                France & New-France customs... and please excuse my grammar and syntax, my maternal language is French...lol

                It was customary and highly encourage by priests to have illegitimate infant baptised has the legitimate child of the couple willing to raise that child as its own... weither the child belong to a relative , a friend of someone in the family or had just been dropped on their door step... this practive was highly encourage to lower the number of illegitimate children within the community, as well as the social stigma that came with it...
                Basicaly baptizing a child as your own was the most current method of adoption and did not leave any paper trail... that was the ancestor of "private and close adoption", so to speak...lol

                In New-France (colonies) that also included inter-racial non official adoptions... weither you are talking about a native infant that was left on the door step of a white or metis couple... or a white or metis infant being dropped in a native village...
                And it did reach a point when priests in general tried to put a stop to those inter-racial exchange of illegitimate children, but it did not worked, the custom was already too deeply rooted to get rid of it that easily...

                So, in short... the number of illegitimate children was more higher than what we can trace in records and there is a high number of ancestors, some even recent, who's parents on records are not really their biological parents...

                Since this practice was well spread amongs the French and encourage by catholic priests... it stands to reason to believe that other European groups may have done the same...

                We do have to remember social mentality and up to very recently, having illegimate children, communly called "bastard", was considered as very shamefull... illegitimate children were considered the result of one of the worst sin possible...

                Based on that and on the fact that surnames did not stabilised equily everywhere and at the same time... exact surnames should not be a factor when looking for commun male ancestors... from a logical stand point, doing that is a huge mistake that would automaticaly falsify the results...

                Non-surname matches absolutely need to be taken into consideration, if we want to accuratly reconstruct male lines, there is no way around it...

                Comment


                • #9
                  In western Finland, surnames didn't become commonplace until the 19th century, and have been required by the law just since 1920s. My surname was adopted by my great grandfather about 100 years ago. His father's surname was different and also his grandfathers surname was different from both of them.

                  There also were nationalistic movements in early 20th century Finland where hundreds of thousands of people changed their Swedish surnames into Finnish ones.

                  Most Icelanders still don't use a surname.

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                  • #10
                    Similarly in The Netherlands, surnames were not required until about 1810 when Napoleon was in control. Many people did not believe surnames would last and, as a result, I know of some families where one son's last name would be "butter", one "mustard", and another the english equivalent of Johnson. Some people even took on names like "Naaktgeboren" (born naked) as a joke. Now the joke is on their families, although some of the worst jokes have been corrected through legal name changes.

                    John

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                    • #11
                      I have Dutch ancestry. Many of my forebears settled in New Netherland in the mid-17th century, and they had surnames, and serious ones, too. Maybe they weren't mandated by law until 1810, but it is pretty apparent that most of the Dutch had them well before then.

                      Of course, a couple of mine were Danes who married Dutch women.

                      Comment


                      • #12
                        Originally posted by Stevo
                        I have Dutch ancestry. Many of my forebears settled in New Netherland in the mid-17th century, and they had surnames, and serious ones, too. Maybe they weren't mandated by law until 1810, but it is pretty apparent that most of the Dutch had them well before then.

                        Of course, a couple of mine were Danes who married Dutch women.
                        They may have been from a certain social class?

                        In Finland, surnames were used by nobility, clergy, civil cervants, craftsmen, military and merchants. Farmers and farm laborers, who were a vast majority back then, didn't use surnames. If they joined the military, they were given a surname, but it wasn't necessarily inherited by their children. For example, one of my ancestors in the 18th century was a soldier, his surname was Mulin, his son was also a soldier but his surname was Fält.

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