Survival of the Fittest
... The main theme of The Call of the Wild is the law of club and fang or "Survival of the Fittest. ... Natural selection is a theory which states that evolution occurs because those individuals of a species, whose characteristics best fit them for survival, are the ones who contribute most of the offspring to the next generation. ... It leans towards an evolutionary view of life, stating that the fittest will survive to have descendent who are even more fit. ... These are different sources of the main theme, the “Survival of the Fittest.