Prior to the changes, humans had been breeding dogs as companions for thousands of years. However, most dog breeds recognized today were developed in the last 150 years, spurred by what’s become known as the Victorian Explosion. During this time in Great Britain, dog breeding intensified and expanded. The downside of this extensive breeding program was the loss of genetic diversity, and changes that had detrimental breed-specific health consequences.
But for dogs...all this had been erased...and rewritten onto humans. Humans were bred for temperment and desirable physical traits...It was why Jax was so much smaller now, his of the several hundred breeds of humans the dogs had created was bred to a smaller size. There were also humans running around who were much larger, who could run longer...who were bred as hunting animals...increasing their ability to sniff out game, which explained the enlarged noses.
One effect of the selective breeding was that most of them were simple creatures eager to please their masters.
"Jax...come on, boy," Jenna said. "Why are you just standing there...your friends are all here..."