Book excerpt: NATIONAL BESTSELLER • “Exciting and provocative . . . A tour de force of a book that begs to be seen as well as to be read.”—The Washington Post Book World World renowned scientist Carl Sagan and acclaimed author Ann Druyan have written a Roots for the human species, a lucid and riveting account of how humans got to be the way we are. Shadows of Forgotten Ancestors is a thrilling saga that starts with the origin of the Earth. It shows with humor and drama that many of our key traits—self-awareness, technology, family ties, submission to authority, hatred for those a little different from ourselves, reason, and ethics—are rooted in the deep past, and illuminated by our kinship with other animals. Sagan and Druyan conduct a breathtaking journey through space and time, zeroing in on critical turning points in evolutionary history, and tracing the origins of sex, altruism, violence, rape, and dominance. Their book culminates in a stunningly original examination of the connection between primate and human traits. Astonishing in its scope, brilliant in its insights, and an absolutely compelling read, Shadows of Forgotten Ancestors is a triumph of popular science.