Thursday, August 2, 2012

McCain Autosomal DNA

I have had several inquires into the Family Finder test that we are now using.  Below is an overview of the autosomal DNA testing with the McCain DNA Project. 

We have several members of the McCain DNA project that have done or are having done the Family Finder test which uses autosmal DNA.  One member has already had a cousin match appear with someone that lists Hance Hamilton as an ancestor.  This is very encouraging and bodes well for when we get more of the autosomal tests completed. 

Autosomal DNA tests are used to locate relative connections along any branch of a family tree.  Any autosomal match between two individuals indicates a possible genetic connection, however in some cases the connection is so far back that the shared DNA has essentially been eliminated through too many generations of recombination . There is nothing in this test that will tell you which branch of your family the match is on so some old fashioned paper genealogy is still needed to sort out the connection.  Obviously, if a match lists Hance Hamilton or a Hugh McKean as an ancestor, then that tells much. One can also have parents, grandparents, cousins, and other family members tested and this will help narrow down potential matches.

The chance that an autosomal DNA test will accurately detect a relative decreases with the distance of the relationship. For example, most autosomal DNA ancestry tests predict an accuracy rate of 90–98 percent when detecting a match with a 3rd cousin, but around a 45–50 percent chance of detecting a match with a fourth cousin. However there is a remarkable aspect of autosomal testing... depending on the DNA recombination an autosomal test will sometimes accurately detect more distant cousins (fifth cousins and beyond).  Also of great utility is double descent from a common distant ancestor (e.g. marriage of second cousins) may potentially increase the chance of a match.  And I have observed that marriage of cousins was common within our McCain clan (as it was with many families in times past).  Given the nature of settlement on the frontier, one almost had to marry a cousin, albeit, second or third, etc.,

Both male and female McCain descendant can participate in the autosmal DNA testing.