Our human ancestors in Africa likely had dark skin, which is produced by an abundance of the pigment eumelanin in skin cells. Darker skin offers protection from the damaging effects of ultraviolet (UV) radiation. Penn State University anthropologist Dr. Nina Jablonski explains that the variation in skin color that evolved since our human ancestors migrated out of Africa can be explained by the tradeoff between protection from UV and the need for some UV absorption for the production of vitamin D.
This version of the film pauses at four points where students answer questions about the film to assess their understanding of the concepts presented. After completing all quiz modules, students can view and print their answers.