Re: exact match for 37 markers
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In reply to:
exact match for 37 markers
Marjorie Barron 7/02/09
Not in my experience. Admittedly, my experience may be considered less than extensive as compared to others who are known to post here.
Our surname project has a group-defined haplotype with two individuals who have gone by very different surnames all their lives (still do), yet both are exact 67/67 matches with each other and no worse than a 65/67 match with three others of the project's focus surname, a 36/37 match with two other individuals in the group, or a 33/35 match with the 22 individuals in the group who tested with a different test service lacking two markers not found on the 37 or 67 marker Family Tree DNA panels.
None of the individuals in this group differ by more than 2 from the group defined haplotype on the markers tested by their respective testing companies, even those who tested at less than 37 markers. It is a very tightly related group by Family Tree's published standards. The most distantly documentable ancestor of ANY individual in this group died no earlier than mid-winter of 1684. And most paper trails are generally better than 95 percent verified by our project genealogists, brick walls notwithstanding.
In the case of one of these two individuals, his birth parents were not married and he was adopted at birth, a fact he apparently learned as an adult only within the past decade, after the death of the woman he had known all his life as his Mother (and over 10 years of research into what he thought was his parent's lineages). The other was apparently an NPE event sometime before or during the Civil War, when his surname family and several of our project's surname were both found in the same general area at the time. Pinpointing this one is still un-resolved and will require testing of living male cousins, if any.
I suppose anything is possible, but I'd tend to call the two to which you refer as _definitely_ related, and politely urge a very searching review of the respective paper trails.
Paper trails, you see, are far more prone to errors than is the passing of Y-DNA from generation to generation. The DNA cannot lie but humans can and frequently do go to great trouble to 'cover up' what is socially unacceptable or what they'd rather not admit actually happened.