"They are indeed distant cousins," revealed Gates. "Talk about six degrees of separation, right?"
Gates said he's had some guests agree to do the show and pull out, including Colin Powell, who changed his mind in the span of four minutes, e-mailing, "Changed my mind. I have too many cousins already."
Gates said he first got fascinated with genealogy when "Roots" premiered in 1977.
"Ever since I've had a bad case of 'Roots' envy," Gates said. " I wanted to be like Alex Haley and find my family tree."