Karl.Kluge@g.gp.cs.cmu.edu (04/19/91)
Someone asked why, if diamond would make such a great nanosubstance, sharks don't have diamond teeth, etc. A critical thing to remember about evolution is that it works by adaptation of pre-existing structures. Once teeth had evolved, modifying them to have a radically different chemical composition isn't necessarily very likely no matter how advantageous it might be. [Yes, evolution has a very strong if-it-works-don't-fix-it attitude. Our bodily fluids are remarkably similar to seawater in composition, considering how long it's been... --JoSH]