It is not the way of the Wild to like movement. Life is an offence to it, for life is movement; and the Wild aims always to destroy movement. (1.3)
Death and the wild are pretty clearly linked here, which means that fighting against the wild is the same as fighting against death. Also, check out how effective London's language is. He cuts right to the point, and he doesn't explain why, but you really feel how harsh and nasty and relentless death in the wild can be.
And this was the epitaph of a dead dog on the Northland trail—less scant than the epitaph of many another dog, of many a man. (1.75)
London wants us to know that death can come without a lot of fanfare. It can be sudden and casual, and where it goes down, you might not even have anyone to say good-bye to you. Harsh, isn't it?
The suffocation he experienced was like the pang of death. To him it signified death. He had no conscious knowledge of death, but like every animal of the Wild, he possessed the instinct of death. (7.27)
By fighting against death—fighting to stay alive—White Fang becomes an instrument of death. It's ironic, but it also explains how the natural world works. You're either killing something or getting killed yourself.
He was better fitted for the life than the other dogs, for he had the training of his cubhood to guide him. (14.19)
Death becomes a teacher here… the scariest teacher you ever met. By threatening to kill him so often when he was a cub, Death gives White Fang the tools to fight off the other dogs. It's a steep learning curve, but if you survive it, you're pretty well equipped to handle anything that comes at you.
As in the past he had bristled and snarled at sight of Lip-lip, so now, and automatically, he bristled and snarled. He did not waste any time. The thing was done thoroughly and with despatch. (14.28)
Lip-lip finally gets his in an incredibly brutal way. In this world, death is the ultimate means of getting even.
At first, the killing of the white men's dogs had been a diversion. After a time it became his occupation. There was no work for him to do. Grey Beaver was busy trading and getting wealthy. So White Fang hung around the landing with the disreputable gang of Indian dogs, waiting for steamers. With the arrival of a steamer the fun began. (15.25)
Having spent so much time under the threat of death, White Fang now delivers it wholesale. There's definitely some irony here: the stronger you get—the more you avoid death—the better you get at killing other things. Avoiders of death are also bringers of death. So it's win-win as far as death is concerned.
The basic life of him dominated him again, and his intelligence fled before the will of his flesh to live. Round and round and back again, stumbling and falling and rising, even uprearing at times on his hind-legs and lifting his foe clear of the earth, he struggled vainly to shake off the clinging death. (18.19)
Notice that London doesn't call Cherokee by his name here. He calls him "the clinging death," which is what he represents to White Fang of course. Subtle, ain't he, that London?
Now look here, Mr. Scott, give the poor devil a fightin' chance. He ain't had no chance yet. He's just come through hell, an' this is the first time he's ben loose. Give 'm a fair chance, an' if he don't deliver the goods, I'll kill 'm myself. There! (19.42)
This might be a note about how death works in civilization. It's still there, but there are rules; it's not random or arbitrary. Death comes only for the perceived common good, and then only when "a fair chance" has been deployed.
But it was the multiplicity of laws that befuddled White Fang and often brought him into disgrace. (23.32)
This quote seems to be suggesting that it's not that we don't kill people when we're civilized. It's that we choose when and where it's okay to kill. White Fang has a hard time picking up on that ("It's okay to kill wild rabbits, but not the cat? Okay, let me write that down…"), and London uses that to make a cute point about how arbitrary civilization can be sometimes.
A constitution of iron and the vitality of the Wild were White Fang's inheritance, and he clung to life, the whole of him and every part of him, in spirit and in flesh, with the tenacity that of old belonged to all creatures. (25.29)
Sometimes, fighting death all your life lets you hold it off even in the worst circumstances. London also makes an observation about death, and the way that every creature in life is defined by fighting against it.