Evolution ... is opportunistic, hence unpredictable.

A species is a reproductive community of populations reproductively isolated from others that occupies a specific niche in nature.

A new species develops if a population which has become geographically isolated from its parental species acquires during this period of isolation characters which promote or guarantee reproductive isolation when the external barriers break down.

Indeed, I was unable to find any evidence whatsoever of the occurrence of a drastic evolutionary acceleration and genetic reconstruction in widespread, populous species.

Evolution ... is opportunistic, hence unpredictable.

A species consists of a group of populations which replace each other geographically or ecologically and of which the neighboring ones integrate or hybridise wherever they are in contact or which are potentially capable of doing so (with one or more of the populations) in those cases where contact is prevented by geographical or ecological barriers.

There is more to biology than rats, Drosophila, Caenorhabditis, and E. coli.