Easy, pure evolution. Human groups that intentionally or unintentionally fed surrounding wolves are at an advantage. The presense of wolves near the humans wou

Easy, pure evolution. Human groups that intentionally or unintentionally fed surrounding wolves are at an advantage. The presense of wolves near the humans would drive off more aggressive predators, which also helps up the local prey populations. Human groups that did not feed or intentionally drove off wolves are at a disadvantage and more likely to be eaten during the night, or be out-competed for food. Repeat for a million years or until your wolf grows eyebrows. Additionally, wolves share their hunt with their pack. It's possible that some early groups were fed at least partially by the wolves hunting for them. If that dynamic ever got established, that group would be at a tremendous advantage.