Work

Character Displacement and the Origins of Diversity

Year: 2010

Type: article

Abstract: In The Origin of Species, Darwin proposed his principle of divergence of character (a process now termed "character displacement") to explain how new species arise and why they differ from each other phenotypically. Darwin maintained that the origin of species and the evolution of differences between them is ultimately caused by divergent selection acting to minimize competitive interactions between initially similar individuals, populations, and species. Here, we examine the empirical support for the various claims that constitute Darwin's principle, specifically that (1) competition promotes divergent trait evolution, (2) the strength of competitively mediated divergent selection increases with increasing phenotypic similarity between competitors, (3) divergence can occur within species, and (4) competitively mediated divergence can trigger speciation. We also explore aspects that Darwin failed to consider. In particular, we describe how (1) divergence can arise from selection acting to lessen reproductive interactions, (2) divergence is fueled by the intersection of character displacement and sexual selection, and (3) phenotypic plasticity may play a key role in promoting character displacement. Generally, character displacement is well supported empirically, and it remains a vital explanation for how new species arise and diversify.

Source: The American Naturalist

DOI: 10.1086/657056

Authors: David W. Pfennig, Karin S. Pfennig

Institution: University of North Carolina at Chapel Hill

Language: English

Topic: Animal Behavior and Reproduction

Subfield: Ecology, Evolution, Behavior and Systematics

Field: Agricultural and Biological Sciences

Domain: Life Sciences

Open Access status: green

Funders: National Science Foundation, Foundation for the National Institutes of Health, National Institutes of Health

Award: The origins and maintenance of context-dependent behavior