Anatomy: Comparative Vertebrate

These are parts that share a common ancestry but may look different or perform different tasks today. A classic example is the pentadactyl limb . The humerus, radius, and ulna found in a human arm are the exact same bones found in a whale’s flipper and a bat’s wing. They are "variations on a theme."

Comparative anatomy highlights how environment dictates design. Comparative Vertebrate Anatomy

At its core, vertebrate anatomy is about patterns. All vertebrates—animals with backbones—share a common structural plan: a dorsal hollow nerve cord, a notochord, and pharyngeal slits at some stage of development. These are parts that share a common ancestry