What are the three examples of the theme survival and one quote

Buck knows when to fight and when not to fight, survival also means being intelligent as well as being strong. Buck resolves to stand down but never accept a rope again,

"He was glad for one thing: the rope was off his neck. That had given them an unfair advantage; but now that it was off, he would show them. They would never get another rope around his neck. Upon that he was resolved." (Ch. 1)

When the men beat Buck, he knows it but he also knows he is not broken,

"He was beaten (he knew that); but he was not broken. " (Ch. 1)

Buck realizes there is no such thing as fair play in the wild if one wants to survive,

"So that was the way. No fair play. Once down, that was the end of you. Well, he would see to it that he never went down." (Chapter 2)