"Anyone with a sixth grade education in biology, much less anyone who breeds dogs for a living, knows that broadening a genetic pool as much as possible results in more genetic health. Heck, that's how DNA and evolution WORK."

That isn't how evolution works either. New species arise when a small group of organisms which move into a new area are cut off from the larger population. It's the effects of the new environment on an isolated gene pool that allow for the new traits to become concentrated and established within the population. Over the course of many generations, the isolated population will become a distinct species, or subspecies of its own. Take the subterranean salamander for example. Its skin is paper thin and completely transparent, and its eyes are underdeveloped buds and useless because the need for eyes and pigment in a pitch black environment is nonexistent. The small group of individuals that first went underground had eyes and thicker skin, but over the course of many generations the genes for these traits atrophied for lack of use. Had this group of salamanders been supplied with a constant source of fresh genes from the outside, then they would have never developed the traits for their new environment.

Contrary to what most people believe, evolution isn't a result of just random mutations. Instead, it's the result of how the environment, over time, shapes and molds life. Just as wind and rain sculpts rock and earth, so to does the environment shape organisms.

Here's a good article on the subject.

Lee, (Lemark was ahead of his time.)