Good question, @davidjblazo. I’d go with your second conclusion. God very foresightedly designed creatures with the ability to adapt to changing environments. That is, He included within the genes of each species the ability to produce offspring with a wide range of characteristics that would enable some to survive even the harshest of conditions.
For example, the two dogs that left the ark would’ve had the ability to produce puppies with short, medium or long hair. As their offspring spread northward into Europe and southward into Africa, climactic conditions would enable some offspring to thrive and others to decline. The further north they migrated, the better the longhaired offspring would fare. Those with short or medium hair would either turn south or die - taking their short and medium haired genes with them.
Eventually, the northern dogs would become depleted of short or medium haired genes. If the climate ever shifted so that the northern regions became hot, these long haired breeds would not be able to readapt because the genetic richness of their parents would be lost.
A similar process would also take place with the short haired southern dogs.
Of course, these would not have diverged into two completely different kinds of animals, because you could always mate a northern dog with a southern and re-enrich the next generation all over again. The fact that they could mate at all shows that they are both still dogs.
Now this highlights a key difference between evolution and adaptation. Evolution depends upon the creation of entirely new and benevolent DNA which had not existed in the parent genes. Adaptation occurs when there is a loss of old DNA that no longer appears in the genes of the descendants.
So I would side with your conclusion that God gets the credit for designing creatures with the ability to survive in what He foresaw would become a fallen world.
I hope this helps you with this question.