While a surname itself may give us incomplete, misleading or only general information about the origin of a family, DNA-testing can give us concrete evidence for identifying and separating family lines. Y-chromosome DNA testing is especially helpful because the male Y-chromosome is handed down, father to son, unchanged through the generations, except for occasional mutations which, in themselves, can be helpful indicators of branching of a family tree. The accessibility and affordability of FamilyDNA testing is doubtless the greatest technical advance in the history of genealogical research because -- at long last -- we have a tool to break down those brick walls!