Smile!  Scientists use enamel, dentin, and pulp to show a link between Neanderthals and early modern humans.

The condition and outward appearance of teeth can tell archaeologists lots of things about ancient civilizations - things like what their hygenic habits were like, what food they ate, and average age of death.  In a new study, the insides of teeth have been analyzed to show that a group dubbed "modern humans" actually continued evolving.