Bolnick Daniel I, Svanbäck Richard, Fordyce James A, Yang Louie H, Davis Jeremy M, Hulsey C Darrin, Forister Matthew L
Section of Evolution and Ecology, Center for Population Biology, Storer Hall, University of California, Davis, California 95616, USA.
Am Nat. 2003 Jan;161(1):1-28. doi: 10.1086/343878. Epub 2002 Dec 11.
Most empirical and theoretical studies of resource use and population dynamics treat conspecific individuals as ecologically equivalent. This simplification is only justified if interindividual niche variation is rare, weak, or has a trivial effect on ecological processes. This article reviews the incidence, degree, causes, and implications of individual-level niche variation to challenge these simplifications. Evidence for individual specialization is available for 93 species distributed across a broad range of taxonomic groups. Although few studies have quantified the degree to which individuals are specialized relative to their population, between-individual variation can sometimes comprise the majority of the population's niche width. The degree of individual specialization varies widely among species and among populations, reflecting a diverse array of physiological, behavioral, and ecological mechanisms that can generate intrapopulation variation. Finally, individual specialization has potentially important ecological, evolutionary, and conservation implications. Theory suggests that niche variation facilitates frequency-dependent interactions that can profoundly affect the population's stability, the amount of intraspecific competition, fitness-function shapes, and the population's capacity to diversify and speciate rapidly. Our collection of case studies suggests that individual specialization is a widespread but underappreciated phenomenon that poses many important but unanswered questions.
大多数关于资源利用和种群动态的实证研究和理论研究都将同种个体视为生态上等价的。只有当个体间生态位变异罕见、微弱或对生态过程影响微小时，这种简化才是合理的。本文回顾了个体水平生态位变异的发生率、程度、原因及影响，以挑战这些简化观点。在广泛的分类群中分布的93个物种都有个体特化的证据。尽管很少有研究量化个体相对于其种群的特化程度，但个体间的变异有时可能占种群生态位宽度的大部分。个体特化程度在物种间和种群间差异很大，反映了一系列能产生种群内变异的生理、行为和生态机制。最后，个体特化具有潜在重要的生态、进化和保护意义。理论表明，生态位变异促进频率依赖的相互作用，这可能深刻影响种群的稳定性、种内竞争量、适合度函数形状以及种群快速多样化和物种形成的能力。我们收集的案例研究表明，个体特化是一种广泛存在但未得到充分认识的现象，它提出了许多重要但未得到解答的问题。
