To quote the witch in Snow White "Who's the fittest of them all?" Who but those who think they are powerful enough to occupy colonies who supply raw materials to be shaped into manufactured articles, to be sold back to the colonies?
That is the definition of imperialism. It is the colonization by force of those unable to prevent the colonization. Imperialism is the creation of an empire by colonizing people that can't prevent their own subjugation.
Does that not sound like survival of the fittest to you?
Society began to crumble and people abandoned their homes and moved east
The correct answer is "none of the above". Mark Twain's "War Prayer" poem stated that there is a part in people´s prayer which they implicitly wish for but do not mention, which is the desire of the destruction and suffering of their enemies. This poem was written as a response to the Spanish-American War.
What the poem emphasizes in are the consequences that result for nations submitted to conflicts, which are al the hardships the people are left with after the war is over.
This reference came from a comedian named Will Rogers, he used it do describe President Herbert Hoovers stimulus efforts during the Great Depression.