Somewhere along the way, humans learned they could breed dogs for particular jobs. Mating two fast dogs produced young that were also fast. The same was true for dogs that could dig, herd animals, hunt or attack humans.
The various breeds look the way they do because sometime in the distant past humans wanted a dog for specific service to people, said Lynch.
Hmmmm. Early neanderthal geneticists. Who knew?
"The same was true for dogs that could dig, herd animals, hunt or attack humans"
....shoot, type, and do basic automotive repair.
(We're still working on the Yo-Yo part)