The structures present in an organism that has lost all or most of its original function in the course of evolution are called vestigial organs. In humans the vestigial organs include, the muscles of the ear (Auricular muscles), wisdom teeth, the Vermiform appendix, the coccyx, body hair, and the semilunar fold in the corner of the eye (Nictitating membrane). Charles Darwin listed a number of putative human vestigial features.