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JWGrace99
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« on: February 21, 2009, 01:58:49 PM »

In recent weeks I have become aware that I share an exact 67 marker match with several individuals who do not share my surname. The surnames are Grace, Love and Winegarner.

I recognize that DNA matching is all about probabilities, but finding these exact matches at the 67 marker level appears to approach improbability. I mean, only a few thousand DNA results  have even been posted. Finding multiple matches at this depth in such a small sample would seem to imply that I share 67 marker DNA matches with several hundred (perhaps several thousand) people, most of whom don't share my surname.

Do we need a 134 or a 268 marker test?

Has anyone had a comparable experience?

John
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Terry Barton
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« Reply #1 on: February 21, 2009, 09:51:50 PM »

Hi John.  First, add a zero to the number of folks tested who have a 67 marker result - as FTDNA says they have 21,737 67 marker records.

I'd like to see us using 2 to 4 times as many markers, as they have the possibility of helping us find the branching within families.  But - I'm not sure how meaningful the extra markers would be for you in this particular circumstance.

For your purposes, 67 markers are sufficient to confirm to you that you share "recent" common ancestry with these men.  The question becomes: how recent? 

Actually, your matches aren't perfect 67/67 marker matches.  One is 65/67 and the other is 62/67.  That's still close enough to be of interest - but nearly as close as a pair of 67/67 matches would be. 

And - the next question is  - What's the story?  How do three different surnames have this match?

Have you compared paper trails and info with these folks who match you?  That should be your next step.  I'd personally start with the 65/67 match - but both are very likely to be meaningful in the genealogical timeframe

And- there is a small possibility that these are distant matches - coming from "convergence" of results of distantly related families.  I see that you have 885 12 marker matches and are a "WAMH" - Western Atlantic Modal Haplotpe - which is simply the most common result at 12 markers that you can have.  There is a very large pool of men with this result - so it is theoretically possible that these are "false" matches - but the probabilities are biased strongly to suggest that these two men are related to you

Terry

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