Final answer:
Darwin's principle of "survival of the fittest" is an integral part of the concept of natural selection, which is the process through which advantageous traits become more common in a population due to differential survival and reproduction.
Step-by-step explanation:
Darwin's principle of "survival of the fittest" suggests that those members of a species with trait variations that contribute to their survival are more likely to pass those traits on to succeeding generations. This concept closely follows the idea of natural selection.
Natural selection requires variability in traits, differential survival and reproduction, and inheritance of traits. Individuals with traits that increase their reproductive success are more likely to pass on these advantageous traits to the next generation. Over time, these traits become more common in the population, leading to evolutionary changes.
Darwin and Wallace both independently concluded that natural selection explains how and why populations evolve. Darwin detailed these ideas in On the Origin of Species, emphasizing that natural selection is the mechanism for adaptive evolution and biodiversity.
Therefore, the concept from the choices provided that Darwin's principle of survival of the fittest follows is a) Natural Selection.