Concept:
An ecological niche refers to the functional role and position of a species within its ecosystem.
Step 1: Origin of the term.
The term “niche” in ecology was first introduced by Charles Elton in 1927.
Step 2: Meaning of niche.
It includes how an organism interacts with biotic and abiotic factors, including its habitat, food, and role.
Step 3: Evaluating the options.
- John Ray $\rightarrow$ Early taxonomist (incorrect)
- Charles Darwin $\rightarrow$ Evolution theory (incorrect)
- Jordon $\rightarrow$ Not associated (incorrect)
- Charles Elton $\rightarrow$ Introduced niche concept (correct)
Step 4: Conclusion.
Thus, the term “niche” was first used by Charles Elton.