Final answer:
The question revolves around the competitive exclusion principle, which states that two species cannot coexist long-term if they occupy the same ecological niche due to competition for resources. The correct answer is that the competitive exclusion principle dictates that one species will undergo local extinction when competing with another species for the same niche. Therefore, the correct option is c) The ecological niche theory; adaptation.
Step-by-step explanation:
The student's question pertains to a fundamental concept in ecology known as the competitive exclusion principle. The correct fill-in-the-blank answer to the student's question is: The competitive exclusion principle states that two species with overlapping niches cannot survive together. Local extinction of one of the species will occur. This principle suggests that if two species attempt to occupy the same niche, they will compete for resources, and eventually, one species will outcompete the other, potentially leading to the local extinction of the less competitive species.
An exemplification of this principle can be observed in the case of two protozoan species, Paramecium aurelia and Paramecium caudatum. When these are grown separately in a controlled laboratory environment, they flourish. However, when placed together in the same habitat, P. aurelia outcompetes P. caudatum for food, causing the latter to face local extinction. Thus, this principle is an essential part of understanding biodiversity and species interactions within ecosystems.