Modelo superior de abundância pode permitir a evolução gradual do mimetismo batesiano: um texte experimental

High-model abundance may permit the gradual evolution of Batesian mimicry: an experimental test

David W. Kikuchi* and David W. Pfennig
- Author Affiliations

Department of Biology, University of North Carolina, Chapel Hill, NC, USA
*Author for correspondence (dkikuchi@email.unc.edu).

Abstract

In Batesian mimicry, a harmless species (the ‘mimic’) resembles a dangerous species (the ‘model’) and is thus protected from predators. It is often assumed that the mimetic phenotype evolves from a cryptic phenotype, but it is unclear how a population can transition through intermediate phenotypes; such intermediates may receive neither the benefits of crypsis nor mimicry. Here, we ask if selection against intermediates weakens with increasing model abundance. We also ask if mimicry has evolved from cryptic phenotypes in a mimetic clade. We first present an ancestral character-state reconstruction showing that mimicry of a coral snake (Micrurus fulvius) by the scarlet kingsnake (Lampropeltis elapsoides) evolved from a cryptic phenotype. We then evaluate predation rates on intermediate phenotypes relative to cryptic and mimetic phenotypes under conditions of both high- and low-model abundances. Our results indicate that where coral snakes are rare, intermediate phenotypes are attacked more often than cryptic and mimetic phenotypes, indicating the presence of an adaptive valley. However, where coral snakes are abundant, intermediate phenotypes are not attacked more frequently, resulting in an adaptive landscape without a valley. Thus, high-model abundance may facilitate the evolution of Batesian mimicry.

adaptive landscape Batesian mimicry coral snake mimicry predation colour pattern

Footnotes

Received November 2, 2009.
Accepted November 9, 2009.
© 2009 The Royal Society

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