text: G. Evelyn Hutchinson formally defined these entities as n-dimensional hypervolumes.
full_question: G. Evelyn Hutchinson formally defined these entities as n-dimensional hypervolumes. These entities are often plotted on bell-shaped utilization curves along a resource spectrum above variables like prey size. Joseph Connell's studies of barnacles on rocks documented the concept of the "realized width" of these entities. Natural selection assigns these entities to competing species in a process alternatively called (*) "partitioning" or "differentiation." An example of animals "constructing" this kind of entity by altering the environment is beavers buildings dams. When different species eat the same prey, these entities overlap. For 10 points, name this ecological concept that describes the roles that organisms play in their habitats.
first_sentence: G. Evelyn Hutchinson formally defined these entities as n-dimensional hypervolumes.
raw_answer: ecological niches 