I already knew about larger and smaller dogs becoming interfertile (but they would not do that without the "artificial insemination technique") I love animals (i've already had 4 cats, dogs, a dwarf rabbit, an iguana, and a cockatiel) but larger and smaller dogs being able to reproduce together does not support the evolution theory.
Besides, the larger and smaller animals still need "help" with their breeding. You can't expect me to believe that, thousands of years ago, a st. bernard ancestor and a terrier ancestor made the first 'batch' of a modern species of dog on their own.
Also, 'kind' is defined as whether or not they can reproduce. if they can bring forth offspring on their own, without any 'help' then they are the same kind of animal. I once saw a first-grader taking a test--the teacher asked "which kind does not belong with the others?" In front of the child was (a) a dog (b) a wolf (c) a coyote (d) a banana. Being only 5 or 6 years old, the kid was smart enough to guess the right answer--even if the banana had been replaced by a cat, there is no doubt in my mind that the kid still would have answered the question right.
Besides, it is not totally uncommon for a wolf and a dog to crossbreed on their own.
In Christ,
Booboo