Useless body parts

By the time you were in middle school, chances are you knew someone who'd had their tonsils or appendix out (or had undergone one of these procedures yourself). I remember it happening so often, in fact, that I lived in constant fear of suddenly being rushed to the hospital for an emergency operation -- and I wondered, once I'd had the surgery, how would life be different? What would change once I was missing these seemingly important parts of my body?

Obviously, the answer is "nothing." It's common knowledge that both the appendix and the tonsils are "useless" body parts, in that the only reason they're a part of our bodies is because they served a purpose for our evolutionary ancestors.

But did you know that our bodies are full of parts like this? Take, for instance, the extrinsic ear muscles, which allow people to move their ears like rabits and dogs do -- amusing, but otherwise pointless. Or how about wisdom teeth? Early humans chewed a lot of plants, so a third row of molars was helfpul, but these days only 5% of the population has a healthy set. Other odd (and ultimately useless) body parts include male nipples, erector pili (the muscle fibers that would allow you to puff your fur, if you had any -- instead they just cause goose bumps), and the firth toe (which is fairly pointless now that we don't cling from branches like apes).

For a full list of your body's obsolete pieces, check out this 2004 Discover article.