Henry Louis Gates, Jr. traces the family trees of Francis Collins, Shirley Ann Jackson, and Harold E. Varmus — three pioneering scientists who've made dramatic contributions to our understanding of the world, all the while knowing little about their own ancestry. 

Henry Louis Gates, Jr. explores the roots of talk show host Jimmy Kimmel and actors Marisa Tomei and John Turturro, introducing them to ancestors who made immense sacrifices to bring their families from Italy to America.