With so many industrious components keeping you moving through your life, it can be startling to think about the number of body parts that, frankly, you just don’t need. The first ones that come to mind often are the appendix and the wisdom teeth.
The appendix, which does produce a few white blood cells, generally gets to stay put so long as it doesn’t get infected. But that third set of molars does little but cause pain and push around the teeth you really need.
You also have a “tailbone,” or coccyx, which serves no function other than as a high-scoring Scrabble word, and it’s a painful reminder of hard falls on your backside. It’s a collection of fused vertebrae that researchers believe are what’s left of the mammalian tail our evolutionary ancestors once sported.
People have a few other vestigial organs. Men, believe it or not, have an undeveloped vestigial uterus hanging on one side of the prostate gland, while women have a vestigial vas deferens — a cluster of tubules near the ovaries that would have become sperm ducts if they had inherited a Y chromosome from their fathers.