Rhino horns and paper cups: deceptive similarities between natural and human designs

One cannot assume that resemblances between the mechanical devices of human technology and those produced by the evolutionary process reflect either specific copying of nature by people or some particular point of functional superiority. A third alternative is that the two mechanical contexts derive quite different advantages from a given arrangement. While this latter might appear unlikely, one can argue that it underlies such things as the use of conical shapes, helical tensile structures, spheres and cylinders, beams and columns of relatively low torsional stiffness, and geodesic shells.