Answer: D - When two populations have overlapping niches, only competition or symbiosis occur. An interaction follows any time two populations share the same niche.
Key Takeaway: An organism’s niche defines virtually every aspect of its existence, including its diet, habitat, and life history. A well defined niche for every type of organism is essential for the stability of an ecosystem. If two populations share the same niche, some interaction must take place to resolve this issue. Whether the interaction is competition or symbiosis, the end result will always be that one or both of the populations will have a modified niche.
