[Phileleutherus Franciscus]

So, you mean if robins and an owls get segregated on an island somewhere, they will eventually mate to become a whole new species of bird?

Since robins and owls cannot interbreed (their last common ancestor was a looooong time ago), no. What would happen, if the survival pressures were sufficient, or the time was long enough, is that the robins and the owls on the island would change enough that they could no longer interbreed with the robins and owls on the mainland. What visible changes might accompany those changes would depend on how different the survival traits optimized for the island were from the survival traits optimized for the mainland.

[autumnraine]

So an entirely new species would not be created, they would just be genetically incompatible with others? I mean they would still be a robin and an owl, but adapted for their environment, right? You said “What visible changes might accompany those changes would depend on how different the survival traits optimized for the island were from the survival traits optimized for the mainland.”

That is adaption, right? It is not a robin turning into an entirely new creature. Just a genetically adapted to the environment robin.