Why Are Ear Muscles Vestigial?

The external ear muscles that connect the ear to the scalp are considered to be vestigial because they provide full movement of the ear for other mammals but are nonfunctional in humans. Animals such as cats can turn their ears to aid with hunting or listening for signs of danger.

Some people are able to wiggle their ears, but in order to change the direction of hearing, humans have to move the entire head. Another vestigial body part found in humans is the remnant of a nictating membrane in the corner of the eye. In birds and reptiles, this third eyelid is used to protect the eye, but in humans, only the nonfunctional remnant remains.