..."why haven't we found any real examples of intermediate species anywhere in the fossil record." - BB
Perhaps you are looking in the wrong place. If you want to find intermediate species maybe you should try watching the westminster dog show.
The toy class may soon enough (2,000 years?) be a different species from the large breed classes. They already face great difficulty interbreeding, which is one aspect of speciation.)
So how long does it take a toy poodle to evolve into an orangutang? Or a grizzly bear? You're still talking about a dog changing into another type of dog - whatever the size or appearance.
Oh - and the difficulty with inter-breeding might be related to relative sizes. It's probably difficult for a chihuahua and Great Dane to mate and I can imagine motherhood would be rather difficult for the chihuahua.
"The toy class may soon enough (2,000 years?) be a different species from the large breed classes. They already face great difficulty interbreeding, which is one aspect of speciation.)"
One of the characteristics of such dogs is usually the great mutational load that they carry. This is indicative of the creationist model, where mutations that are carried within the population are normally bad. You can create a decrepit dog that has trouble interbreeding with genetically healthier dogs, but how does this fit within a theory of evolution that has a generally upward movement of complexity? (I know that the theory itself does not say "upward movement", but every evolutionary tree I've ever seen starts with pre-biotic material, moves towards bacteria-like organisms, then to single-celled organisms, then to multicellular life, then to more complex multicellular life, so there must be some sort of general upward direction)