Does the science of dog breeding provide the best way to explain the genetic mechanisms behind evolution?

I have been attempting to figure out a way to explain, particularly to myself, a simple way to determine the genetic explanations behind the most “controversial” mechanisms of evolution.

The genetic nature of dog breeding seems to be the best one, and it explains, for me (1) the introduction of genetic infomation that creates new traits that weren’t there before, (2) the minor amount of genetic change necessary to make big differences, and (3) the ability of the environment to cause sharing of genetic information cross-species.

The “tandem repeats” in the dog’s genome has been correlated to significant physical changes. These are present in all mammals, but not at all to the extent in dogs. This has been shown why they can change so quickly. They also share 99.8% of their genome, but are so physically different. The size of dogs has been linked to changes in a single gene (IGF-1). This explains how we can be so closely related to things that are so different from us, and also how very little change in protein-coding can create so much difference. Finally, the genetic defects brought in through breeding have shown how genetic material can be introduced through shared environments. Doctors have used viral DNA to introduce material that codes for vitamin A into the bloodstream of dogs going blind for lack of it, and have been able to show that the viral DNA attaches to the dog’s to create a new coding mechanism repairing eyesight.

What do people think? And are there any other examples that can show, generally and solidly, the genetic (arguably the more difficult) mechanisms behind diversification?