Hello Frances.
It was the 3x great grandson of Thomas Corkill and Elizabeth Lewin that produced the DNA signitures that John Creer was talking about on the message board today. My goal would be to try to push the family line further back and maybe one day find the Corkill split that led to the other person tested. I have considered the possibility that William Corkill and Margaret Farghar are the parents of Thomas (bpt. 16 Jul 1777, St. Mathews, Douglas), and that the parents of his father William are either John Corkill and Sarah Brideson (bpt. 28 Jul 1754) or John Corkill and Margaret Casshin (bpt.12 Dec 1760). Further back from there, it would seem that looking at the John's born in the 1720s-1730s in Maughold might be the way to go. Am I out of my mind?