The mammalian ear is a perfect example. Over the eons, the jawbones of our fish ancestors became three separate small bones that transmit sound waves from the eardrum to the inner ear. Now a new ...

The human outer ear may have arisen from ancient fish gills. | Credit: A. Martin UW Photography/Getty Images (left); Photographer, Basak Gurbuz Derman/Getty Images (right) Humans' outer ears may ...

Fish also have nostrils, which they use for smelling and ears for hearing and to help with ... and warning others about ...