A、Through natural selection. B、Through people’s training. C、Through their members’ protection. D、Through born abilities. A

If we are going to train this dog into the companion that we want him to be,(22)then it is important that we understand what the animal is and what the animal wants to be. Remember that training of dogs is a relatively recent event in the course of their existence. They have been around for millions of years, but only a few thousand of those years with us. By looking back with an evolutionary point of view, we can see they spent a long time forming a life style and the types of behavior that were kept with their existence.(23)In their world, before they lived with us, there were no food bowls setting on the floor always filled with a balanced diet. No individuals, except other pack members, guarded them from injury and there was no large medical industry to protect them from disease.
    Through natural selection a dog model was formed that had the physical and mental abilities to continue their species.
    Their behavior patterns guided them through their day to day and year to year existence, helping them to make the right choices to protect themselves and their offspring. If this wouldn’t have been accomplished they would be classified with the dinosaurs. For dogs, being part of a group of dogs has provided them with many benefits.(25)Much of their natural instinctive behavior centers around learning how to deal with or interact with members of the group.