While a surname itself has been shown to be only a mediocre genealogical marker, it is a starting point for someone.  The revolution of genetic testing has given us an extremely accurate tool in order to verify true genealogical connections and remove those that were based upon myths and suppositions.  But genetic testing alone cannot complete the genealogical story.  Reliable genealogical information is still necessary.  Y-chromosome DNA testing is especially helpful because the male Y-chromosome is handed down, father to son, unchanged through the generations, except for rare mutations which, in themselves, can be helpful indicators of branching. The accessibility and affordability of family DNA testing is doubtless the greatest technical advance in the history of genealogical research because -- at long, long last -- we have a tool to break down those brick walls!