A DNA Anomaly?

There is a Y-DNA genetic difference with one branch of the Thomas Jameson side of the family. This was discovered with Y-DNA testing, at it's earliest (oldest), with Jon Francis Jameson. Results from both Jon Francis Jameson and his grandson Michael Jon Jameson differ from the generally accepted Y-DNA profile assumed (and verified with the Y-DNA test results from other Jamesons known to be descendants) for this Jameson family. The extent and reasons of this variance has not, so far, been revealed/determined.

Both John Francis and Michael Jon Jameson seem to have impeccable traditional paper trails all the way back to the immigrant ancestor, Thomas Jameson. Yet their Y-DNA test results clearly say otherwise. Both of these individuals were raised as Jamesons and always understood their descendancy and heritage to be as it appears here in this genealogy.

All of the Y-DNA test results for our entire family, which is to say both the Thomas and the Hugh sides[1] are surprisingly similar, given the more likely chance they be considerably different if Thomas and Hugh were not actually brothers. They all even share the same basic Haplogroup. Yet one branch of the Thomas side of the family varies within nine places in the first 37 DYS marker locations, part of the test. Although they are close, this is more then enough of a difference to suggest no close relationship, for maybe several thousands of generations.

Extended results however, on the separate SNP side of testing, show a clear divergence to the test results of others tested on both sides of the family, just after the common Z58 (SNP) marker, indicating these two families took a different path, about what experts believe may have been 4,000 years ago.[2]

There are any number of possible explanations, although a test error is not likely one of those. Two separate Y-DNA tests done years apart, over different generations, prove that can not be the case. It is most likely that there was a break somewhere in just the chain of descendancy in the one line of families, starting from Alexander and Janet (Moore) Jameson, the eldest son of immigrant Thomas and Margaret (Dickey) Jameson, or maybe with Alexander (1748-1807), himself? Because, the other lines, also descended from Thomas and Margaret Jameson, test alike and the same as all the tests in the Hugh (Thomas' brother) side of the family, as well. This could have been the result of an adopted son, raised as a Jameson, or an issue of unknown paternity. Two common examples of this could be where an unfortunate or unwanted male child was taken into the family and raised as their own, or where the child of a previous marriage was raised in the newer family as one of them. Both possibilities exist for this Jameson family. Although we do not know exactly when or how this occurred, it would have to have been before the birth of Jon Francis Jameson in 1935 and after the immigrant ancestor, Thomas Jameson. b.c.1709, had children (mid 1700's). Focus for clarity on this issue can now be concentrated on just this line of descendancy and not that of any of the other descendants of Thomas and Margaret (Dickey) Jameson.

So, in summary, Y-DNA testing with descendants of both Thomas and Hugh Jameson from early New Hampshire, show they share the same Y-DNA tested results, except for one instance that can put one line (branch) of one side (Thomas) of this family technically outside of at least the DNA "family" connection. Further testing within that branch might narrow where this 'exception' mat have occurred.