Dog breeds

Response

When we create a new breed of dog, we are simply selecting from genetic “options” that were already there. ²

In fact, breeding dogs is like “weeding out” genes.  For instance, if we want dogs with short hair, we eliminate dogs with longer hair.  Over time, fewer and fewer dogs have longer hair as the gene for long hair becomes more and more scarce.  Eventually, no dogs in our new breed will have long hair because we have weeded out all the long hair genes.  Although we have created a distinct type of dog, we have fewer genes than what we started with.

Some dog breeds actually suffer from mutations, like the bulldog and pug’s squashed nose. ³  Veterinarians realize that purebred dogs suffer from more diseases than mutts, ⁴ and this is because purebreds have fewer genes left.  Breeding dogs is a one-way street downhill from lots of genes to fewer genes.  The only way to recover is to breed our population with, say, a wolf to get more genes back.

In summary, breeding dogs is the exact opposite of the type of change we need for evolution.