Precisely. Something taking astoundingly long to evolve isn't conclusive evidence that it's highly improbable (although it might suggest it). It could very well

Precisely. Something taking astoundingly long to evolve isn't conclusive evidence that it's highly improbable (although it might suggest it). It could very well be highly probable. One reason is as you mention is prerequisites. Another reason could be that the solution is deep in the search tree, and while it takes ages to find it, the search algorithm will eventually do so. Consider a global optimizer running on a concave surface for a long period of time, all it needs is time.