This is when Buck sprinting after a bunny trying to kill it, but spitz jumps in front of Buck and kill the rabbit before Buck this show spitz is fit for the wild becuase he knows how to hunt and can survive by himself in the wild.
This is when dolly was bit and turned mad because of rabies eventually the dog driver had to chop her head off otherwise she may hurt the others. This is and example of that dolly was not fit for the wild.
This is when Spitz and Buck fight eventually Buck murders Spitz showing that Buck is the lead dog and that he is more fit for the wild then the other dogs
This is after Spitz is killed where Francois and Peurralt try finding a new lead dog when they found one they strapped him in but buck kept moving him and taking the spot as the lead dog. Eventually Buck is put at lead dog and he was a great one this shows that he is fit for the wild and what ever else is still there to come.
This is when Buck pulls 1,000 pounds of flour and wins the bet John Thortan made, they won 1,600 dollars this shows that Buck was fit for what he was doing when he was pulling the sleds because he truly has talent.
This is when Buck and his wolf brother run through the woods has friends this shows that Buck is ment for the wild like as if he is a wolf.