  We propose a simple "evolutionary" sandpile model exhibiting self-organised
criticality and exactly $1/f$-noise (i.e. the critical exponent is equal to
$-1$) and observe emergent phenomena of the same type self-organised
criticality on the "next level" sandpile. In this way we try to model climbing
by the so-called hierarchy of sciences, where processes on a higher level can,
in principle, be derived by laws of a lower level but this derivation is
computationally unfeasible and useless from the explanatory point of view.
