What ecological concept involves the struggle for resources between two species?

The correct answer is based on the concept of competition, which refers specifically to the interaction between two or more species that vie for the same limited resources, such as food, water, light, or habitat. This struggle for resources is a crucial aspect of ecological dynamics because it can influence the population sizes, behaviors, and evolutionary paths of the species involved.

In an ecosystem, when two species have overlapping niches or similar resource requirements, they must compete to survive and thrive. This competition can lead to a variety of outcomes, such as resource partitioning, where species evolve to utilize different resources or occupy different niches, or even competitive exclusion, where one species outcompetes another for resources, eventually leading to the latter's decline or extinction.

Coexistence refers to species living together in the same environment without necessarily engaging in direct competition for resources. Symbiosis involves interactions between species that may benefit one or both parties, such as mutualism, commensalism, or parasitism. Cooperation implies a form of interaction where species work together to benefit each other, contrasting with the competitive nature of resource struggles. Therefore, the concept that best captures the essence of the struggle for resources between two species is indeed competition.