The purpose of this project is to compare Y chromosome DNA of males with the surnames Dorsey, Darsey, D’Arcy, Dorcey, and Dossey and other variant spellings in order to identify and verify patrilineal lines and connections among families of those surnames worldwide. This project was launched in 2002. As the study grew, our membership expanded to include representatives of a number of well-documented American and Irish Dorsey/D’Arcy/Darsey lines, making it possible to address several specific questions of long standing academic interest. This project is ongoing and we are actively recruiting new members.