Teeth – I have always thought they are one of the weakest links in our evolution, and an example of how nature does not always come up with an optimal design. They just don’t make any sense. Why make them out of substances that dissolve in acid when most of our food is made of acid? They just don’t last as long as most of our other body parts, and they cause us tremendous pain and suffering. Maybe in the future we will just have them all pulled out at some point and replaced with titanium or something else durable. Something I didn’t know, though, is that teeth actually have the ability to heal themselves at a slow rate, and this ability could maybe be accelerated using drugs.