Via BoingBoing, here is a lovely list of kludges under the heading of “worst evolutionary designs.” My favorite
6 Shark-fetus teeth. A few shark species have live births (instead of laying eggs). The Jaws juniors grow teeth in the womb. The first sibling or two to mature sometimes eat their siblings in utero. Mmm … siblings.
I mention viviparous sharks in my paper “Kludged” becuase most sharks lay eggs and requires a large and coordinated mutation to switch to live birth without producing a fatal misfit. This example shows that whatever doesn’t kill it only makes it more kludgey.