Moving Character Displacement beyond Characters Using Contemporary Coexistence Theory. (February 2018)

• Record Type: Journal Article
• Authors: Germain, Rachel M.; Williams, Jennifer L.; Schluter, Dolph; Angert, Amy L.
• Is Part Of: Trends in ecology & evolution. Volume 33:Number 2(2018)
• Page Start: 74
• Page End: 84
• Publication Date: 2018-02
• Subjects: character evolution -- competition -- eco-evolutionary dynamics -- evolutionary rescue -- invasibility criterion -- sympatry; Ecology -- Periodicals; Evolution (Biology) -- Periodicals; 576.8
• DOI: 10.1016/j.tree.2017.11.002
• Languages: English
• ISSNs: 0169-5347

Abstract

Abstract : Character displacement is one of the most studied phenomena in evolutionary biology, yet research has narrowly focused on demonstrating whether or not displacement has occurred. We propose a new experimental approach, adopted from the coexistence literature, that directly measures interspecific competition among sympatric and allopatric populations of species. Doing so allows increased ability to (i) test predictions of character displacement without biases inherent to character-centric tests, (ii) quantify its effect on the stability of coexistence, (iii) resolve the phenotypic pathways through which competitive divergence is achieved, and (iv) perform comparative tests. Our approach extends research to forms of character displacement not readily identified by past methods and will lead to a broader understanding of its consequences for community structure. Trends: Recent evaluations of tests of character displacement suggest major gaps in our understanding. We advocate for adopting an experimental approach from the ecological literature to allow researchers to test long-standing theory about when, where, and how character displacement occurs. The approach adopts an invasibility criterion, and in practice is assessed by measuring the population growth rate of a species when rare competing against a background of individuals of another species from either sympatric or allopatric populations. We show how adopting this approach will provide unbiased demonstrations of whether character displacement is present, as well as reveal its evolutionary underpinnings and ecological consequences.