Our popular image of Homo erectus as the proto-guy who whose human-like traits all emerged at once needs overhauling, some anthropologists say. Sylvain Entressangle/Science Source hide caption

itoggle caption Sylvain Entressangle/Science Source

Signs of tuberculosis have been found in ancient Egyptian mummies, such as this one in London's British Museum. Klafubra/Wikimedia.org hide caption

itoggle caption Klafubra/Wikimedia.org

This model of a molar shows color-coded barium banding patterns that reveal weaning age. Ian Harrowell, Christine Austin, Manish Arora/Harvard School of Public Health hide caption

itoggle caption Ian Harrowell, Christine Austin, Manish Arora/Harvard School of Public Health