Reflections on an essential but elusive ecological metaphor: The Hutchinsonian niche

The Hutchinsonian niche, a pervasive metaphor in ecology, is a sister concept to Sewall Wright’s adaptive landscape, with a shared focus on fitness. Characterizing what fitness means (and how to measure it) is a fundamental conceptual issue in both evolutionary biology and ecology. After a brief overview of adaptive landscapes and issues with fitness, this essay contrasts G.E. Hutchinson’s 1978 30 formalization of the niche as a surface of intrinsic growth rate across environments, with his earlier 1957 formulation focused on population persistence across environments. The former has come to be a prevalent usage of “niche” discourse in the ecological and evolutionary literature, but the latter conceptualization warrants attention, if one for instance wishes to relate niche concepts to species’ 34 geographical distributions. Conceptualizing a species’ niche as a surface of probabilities of persistence across environments requires consideration of factors beyond intrinsic growth rate when rare, including dispersal, demographic stochasticity, and density dependence, among other factors – all elements needed for the metaphor of the Hutchinsonian niche to fully capture its original meaning as a statement about what a species requires from its environment in order to persist.