Thursday, April 23, 2015

Scots-Irish DNA Project Update 23 April 2015

For members interested in a case study of a Family Tree DNA family project that located their cousins in Ulster and eventually located their progenitor in Argyll, Scotland, we suggest the new book  'Finding the McCains'  (on Amazon).   The book shows how a Y-DNA match group can be used to focus research on specific geographic area and the use of the primary sources there.  It is a familiar tale to many researchers.  A 40 year search for family history, the brick wall, then the DNA testing with dramatic results.  It can be a complex task, but it can be done and 'Finding the McCains' is an excellent example of how one Ulster family accomplished this.  The McCains include Senator John McCain, the Canadian family of Wallace and Harrison McCain of New Brunswick, and James McKeen, co-leader of the 1718 Ulster fleet that began the Ulster migration.

I have received several emails concerning ‘genetic convergence’  which can produce a false match:  There was a rapid population expansion in the last 4000-5000 years and some of the lineages within R1b1a2 have experienced convergence of STR values.  This is due to the random mutation process. Some of the more distant lineages have moved closer together producing coincidental matching haplotypes.  This phenomenon is called “convergence” (also known as evolutionary convergence) is the term we use in genetic genealogy to describe the process when two different haplotypes mutate over time to become identical or near identical resulting in an coincidental match. Coincidental matches will often be in different subclades and the common ancestor will have lived several thousand years ago rather than within a genealogical timeframe.   A convergence can produce a “false positive" match.

This is one reason we recommend you test at least 67 markers.  There has been only one case of a convergence match at this level.  The 111 marker level is the best test to filter out any possible convergence match.  This is particularly important for participants Ulster and Scottish ancestry, because surnames were often not fixed until very late, circa 1500 to 1700.  In many cases your non-surname matches are just important as your surname matches, but only if they are bona fide matches.  In our geographic area many clans and families used different surnames as these groups followed patronymic naming customs.  An example of this: a Mac Dónaill family circa 1520 has an illustrious son named Alastair and by 1570 his line uses the surname Mac Alastair.  When a descendant tests he will find anglicized forms of both Mac Dónaill and Mac Alastair present in his match group.  In this example the match group could contain numerous anglicized forms, Alexander, Alastair, Daniels, Donaldson, McDaniels, McDonald, McDonnell, etc.
Address for our blog below; news of the project is posted there.    Best of luck with your genetic genealogy project.  (The Scots-Irish Blog)

McCain's Corner:
Ulster Heritage:
Barry R McCain website:

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