Dog Breeds

The concept of Dog breeds (and cat breeds) has always amazed me.  Long before the concept of genetic animal and food modification became a household popular concept, people were breeding dogs to be better at one specific trait over another.  We're told this happened over time, and simply by breeding dogs with like-suited dogs.

We are to believe that all dogs were alike at one point in the distant history, and by choosing their mates, over time, we are left with 4 foot tall Great Danes and 1 foot tall wiener dogs.  We have super fast racers, and working dogs that know how to bring the sheep home.

At some point, we declare these breeds purebreds, and start paying attention to their pure lineage, and a new bred was born.  All in the far far far away past.

It just doesn't make a whole lot of sense to me that it all happened from one dog centuries ago, and then they stopped.  Somebody said; Ok... 300 breeds is enough... and 300 years passed.

My question is, why did they stop?  It's only recently that they seem to be starting up again, and cross breeding poodles with just about everything, but instead of creating new purebred breeds, they're naming them silly cross-names like Cock-a-poos and Golden-Poos.  I suppose eventually these will be purebreds as more and more of the cross-breeds procreate with their own kind.

As far as I know, we're still doing this the old fashioned way... cross breeding purebreds... not genetics.  We're doing the same thing they did centuries ago. 

I want a small dog that doesn't yap.  Nobody seems to have engineered that one yet.