arrival of the fittest

A priori natural selection:  the universe selects solutions before making them real, in the sense of existing absolutely rather than existing as one solution in a superposition of solutions. This applies to the laws of the universe, life itself, the building blocks of life, genera, species and mutations of species. Solutions are subsequently subject to a posteriori natural selection - survival of the fittest - but that determines which solutions are eliminated, rather than which solutions exist in the first place.