Elena11/Shutterstock Nobody pays much attention to that dangly little thing in the back of the throat, except perhaps some comic animators. Some theories suggest that the uvula—which is fully developed only in humans—helped our ancestors speak or drink while bending over a watering hole for prehistoric refreshment. But its most obvious purpose involves quickly secreting large amounts of saliva (over a lifetime, the average person produces enough to fill two swimming pools). The uvula may also be associated with snoring; according to an Italian study, people who snored had significantly fewer nerve fibers in their uvula than their non-snoring counterparts. Here’s how the uvula got its name.
Victoria Rudakova/Shutterstock Though the hairy strips are especially useful for communicating those “say what?” moments, their main purpose is to protect our eyes from debris, water, and sun. Eyebrows are also a crucial factor in face recognition. When volunteers in an MIT study were asked to identify photos of 50 famous faces with their eyes digitally removed, they could recognize the individuals 60 percent of the time. When the faces lacked eyebrows, however, participants could only ID them 46 percent of the time. In other words, eyebrows are incredibly important for facial recognition.