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  • Guest's Avatar
    Guest replied
    Thank you. vineviz. As you can tell I'm not too familiar with the proper DNA terms. I'm better at reading old handwriting and documents! We've formed a research group and maybe when other McCoy researchers find us on the web we'll have more subjects to test. I appreciate your wisdom. All hope is not lost!
    Judy

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  • vineviz
    replied
    Originally posted by JMcCoy
    Thank you, Jim, for your reply.
    Shouldn't the haplotype of the MRCA be my husband's, R1b1? Father's father's father's, etc.
    R1b1 is their haplogroup. 13-24-14-11 etc is the haplotype.


    Originally posted by jmccoy
    I wonder if we will ever be able to tell if the 1760s men were brothers by DNA?
    As a matter of principle, no, you will not be able to "prove" they were brothers. You might be able to assemble enough evidence to conclude it, if you tested enough descendants of each man. You might need a large number (maybe six or more descendants of each) to do that however. Even finding one or two more in each line would be a big help.

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  • vineviz
    replied
    Originally posted by JMcCoy
    My husband and a man with the same surname and the probable MRCA born circa 1720, took the 37 marker test. They differ at 390 (25,24), 385a (11,12), 439 (12,11), CDYb (37,38), and DYS442 (12,13). I read that 385a and 439 mutate more rapidly than others, but can these two men still share a MRCA within 7 or 8 generations with 5 1-step mismatches? Our genealogical theory was that my husband's g.g.g. grandfather was the brother of the other man's g.g.g. grandfather. Has this been summarily disproven? How distantly would they be related? Another generation or two back, perhaps?
    The results you received would, in my opinion, fall into a frustrating, grey "in between" area.

    Normally, you would expect two men with a common ancestor 6 or 8 generations ago to have less genetic distance than your husband has to your fellow tester. But I would certainly not say that it is impossible that the two GGG grandfathers were brothers.

    On the other hand, if they were not related at all then you would expect them to be have much more genetic distance between them.

    One strategy for gaining clarity is to find other cousins (third or fourth cousins, preferably) of each man to test. This can help you figure out when the different mutations might have arisen.

    With further research, you might also find that the two men that you thought were brothers were possibly cousins instead. Unfortunately, these ambiguous cases are hard to resolve with just two data samples.

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  • Guest's Avatar
    Guest replied
    Thank you, Jim, for your reply.
    Shouldn't the haplotype of the MRCA be my husband's, R1b1? Father's father's father's, etc.
    Genealogically we were trying to prove these 2 men born circa 1760 were brothers. My husband's ancestry is proven but there is not so much proof about the supposed brother b. abt. 1760. I see what you mean about the mutations not being as exclusionary as we thought. They still might be descended from the same man born circa 1720.
    The other McCoy man has not had his haplotype results posted yet.
    I thought this would be a 'slam-dunk' to prove the relationship. I wonder if we will ever be able to tell if the 1760s men were brothers by DNA?
    Thanks again,
    Judy

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  • Jim Barrett
    replied
    No need to be upset. You don't know the Haplotype of the MRCA. If you husband has two one step mutations from him in almost 300 years and the other man has three one step mutations on different markers during that same time frame that would be a very small change.

    If they don't have a lot of other matches that is even a better case for them to be related. When people don't share a common ancestor the genetic difference is usually much greater.

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  • Guest's Avatar
    Guest started a topic Not closely related?

    Not closely related?

    My husband and a man with the same surname and the probable MRCA born circa 1720, took the 37 marker test. They differ at 390 (25,24), 385a (11,12), 439 (12,11), CDYb (37,38), and DYS442 (12,13). I read that 385a and 439 mutate more rapidly than others, but can these two men still share a MRCA within 7 or 8 generations with 5 1-step mismatches? Our genealogical theory was that my husband's g.g.g. grandfather was the brother of the other man's g.g.g. grandfather. Has this been summarily disproven? How distantly would they be related? Another generation or two back, perhaps? The other man's ancestors came to KY with my husband's ancestors, all of the same surname.
    Thank you for any advise, both his family and ours are very confused and upset about it.
    Best wishes,
    Judy McCoy
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