The William Abernathy mentioned by John Abernathy Smith was the eldest child of Charles Abernathy & Alice Short. He was baptized on 13 Jun 1742 in Bristol Parish, Brunswick County, VA. His father was probably born somewhere around 1715, but we have no documents to suggest how he is related to the Abernathy lineage that derives from the Robert Abernathy (cir 1633-cir 1684/5)) of Charles City County, VA.
We have a 67 marker ancestral Y-DNA ancestral profile that defines Robert of Charles City county VA and William of New Haven County, CT and a few undocumented other kin.
We have tested the Y-DNA of five documented, direct male descendants of Charles & Alice: of those five, 1 tested 67 markers with no deviations at all, 2 tested 42 markers with no deviations at all, 1 tested 37 markers with only one deviation and 1 tested 67 markers with 2 deviations.
Of the eighteen individuals we have tested from the Robert-Sarah Cubisha lineage, 1 tested 67 markers with no deviations, 2 tested 67 markers with 1 deviation each, 9 tested 42 markers with no deviations, 3 tested 42 markers with 1 deviation each, 2 tested 42 markers with 2 deviations each, and 1 tested 37 markers with 1 deviation. Of the 2 individuals who descend from William of CT, both tested 42 markers and both had the identical 2 deviations each.
All in all, we presently have 32 individuals in this group who tested 37, 42, or 67 markers and none deviate from the ancestral profile by more than 2 markers, although we cannot document some of these as well as we would like, as we can in the Robert-Sarah Cubisha lineage, the Charles-Alice Short lineage and the David-Ann Lyles lineage which all derive from the same core counties in pre-Revolutionary War colonial Virginia.
That they and a few others are all very tightly related is obvious to us now. But it's precisely _how_ they are relatedthat in some instances is only conjecture.