I know I am posting to an old message but our MOODY Ydna Surname Project recently had an Exact Match between two men, one who spelled his surname as MOOTY which his genealogy shows dates back to a Thomas MOOTY of SC in 1660 and another man who spells his last name MOODY whose family descends from an Alexand MOODY of PA c1780. That they are both Exact Ydna matches says there must be some bit of truth about this spelling change over. I suspected that their name was possibly from the old Scottish name of "Auchmuty" the moment I saw the MOOTY person's name appear in our Ydna project. Either that or perhaps some German variant of the name as well since so many folks of German descent came into PA as well. Hope this may be of help.