Evolution
As the gray wolf is a apex predator, fast and strong this allows it to survive by itself. It is also able to adapt to its environment. Wolves hunt in packs. The head wolf is the provider of food and should it die another dominant wolf will need to step into its place in order to continue hunting.
The gray wolf does participate in group behavior. They both travel and hunt in packs. This behavior gives the gray wolf a good chance of survival as the wolves protect one another. This also allows them opportunity for a better food supply.