A salamander population was divided when a highway was built, cutting off one end of the stream from the pond it had connected to. Over many generations, the salamanders evolved into two completely different species. What is the best explanation for this?
A. fish ate all the slower salamanders.
B. One salamander outcompeted the other for food and resources
C. Humans brought the second salamander over from Europe and started breeding it in the pond.
D. The isolation of each population (along with random mutation) over time made it impossible for the two populations to interbreed with each
other