As early as the 1840s, playwrights incorporated evolutionary theory into their work, reacting to a scientific advancement that changed the world. This book follows evolutionary theory in mainstream European and American drama and other theatrical entertainments, including circus, pantomime, and the "missing link" show. It writes female playwrights into the theatrical record, as they explored biological determinism, gender essentialism, the maternal instinct, and the "cult of motherhood" in their work.