survival of the fittest vs selection

survival of the fittest and selection both are nouns.

Word	Noun	Adjective	Verb	Adverb
survival of the fittest	Yes	No	No	No
selection	Yes	No	No	No

As nouns, survival of the fittest and selection are synonyms defined as:

survival of the fittest and selection: a natural process resulting in the evolution of organisms best adapted to the environment

Other synonyms of survival of the fittest include natural selection, survival.

survival of the fittest (noun)	selection (noun)
a natural process resulting in the evolution of organisms best adapted to the environment	the act of choosing or selecting
	the person or thing chosen or selected
	a passage selected from a larger work
	an assortment of things from which a choice can be made
	a natural process resulting in the evolution of organisms best adapted to the environment