One of the easiest ways to learn anatomy is to relate function with structure. Quite often, the anatomy is intimately connected to its function. Evolution has produced the most efficient structure for the maximum performance of the body. However, bodies are under constant change and as researchers look back at the history of the human, many structures have disappeared or become more prominent. Some vestigial (obsolete and undergoing reduction) structures remain in the body. The appendix is one such structure.

The skeleton is a good place to observe structure and function. As humans began to walk upright, the stress on the sacral vertebrae and pelvic girdles became greater. As a result, the sacral vertebrae fused to make a strong support for the pelvic bones. These bones fused to provide additional strength. The articulation with the femur gained importance since the torso rested on the...