If a sheep is left unshorn, will its wool grow forever? Is that healthy? Is this a glitch in the (wooly) fabric of evolution? Take a moment to drink in the glory of Shrek the Sheep. Shrek really, really, really did not like getting his hair cut. So for six years, this New Zealand libertarian managed to avoid spring shearings by hiding in a cave. By the time he was found in 2004, his owners couldn’