Multiple, recurring origins of aposematism and diet specialization in poison frogs

Abstract

Aposematism is the association, in a prey organism, of the presence of a warning signal with unprofitability to predators. The origin of aposematism is puzzling, because of its predicted low probability of establishment in a population due to the prey's increased conspicuousness. Aposematism is a widespread trait in invertebrate taxa, but, in vertebrates, it is mostly evident in amphibians, reptiles, and fishes. Poison frogs (Dendrobatidae) are one of the most well known examples of the co-occurrence of warning coloration and toxicity. This monophyletic group of mostly diurnal leaf-litter Neotropical anurans has both toxic͞colorful and palatable͞cryptic species. Previous studies suggested a single origin of toxicity and warning coloration, dividing the family in two discrete groups of primitively cryptic and more derived aposematic frogs. Recent molecular phylogenetic analyses using mostly aposematic taxa supported this conclusion and proposed a single tandem origin of toxicity and conspicuous warning coloration. By using expanded taxon and character sampling, we reexamined the phylogenetic correlation between the origins of toxicity and warning coloration. At least four or five independent origins of aposematism have occurred within poison frogs; by using simulations, we rejected hypotheses of one, two, or three origins of aposematism (P < 0.002). We also found that diet specialization is linked with the evolution of aposematism. Specialization on prey, such as ants and termites, may have evolved independently at least two times.

Predator learning favours mimicry of a less-toxic model in poison frogs

“…1b). Their phylogenetically distant relative 13 , Allobates zaparo, is geographically dimorphic, matching each warning signal where models are parapatric (Fig. 1b).…”

Una especie nueva de rana venenosa de altura del género Excidobates (Dendrobatoidea: Dendrobatidae) de la Cordillera del Cóndor

“…Aplicamos la reacción en cadena de la polimerasa (PCR) para amplificar, en cuatro fragmentos sobrelapados, los genes mitocondriales 12S rRNA, Valina-tRNA y 16S rRNA. Los primers utilizados fueron los listados en Santos et al (2003). La amplificación se llevó a cabo con protocolos estándar.…”

“…La mayoría de secuencias provienen de Summers et al (1999), Clough & Summers (2000), Santos et al (2003), Symula et al (2003), Grant et al (2006), Noonan & Wray (2006), Roberts et al (2006), Brown et al (2008), Santos et al (2009) y Brown et al (2011. Los números de acceso al GenBank están listados en la Fig.…”

The benefit of being a social butterfly: communal roosting deters predation

“…Because of these features, Heliconius butterflies serve as a textbook example of warning signalling-also known as aposematism. Aposematism is a major theme in the evolution of animal phenotypes, where its principal function is to provide warning signals associated with unprofitability to predators, such as toxicity, unpalatability or capture costs [19][20][21]. Aposematism is widespread in invertebrates and is often achieved through visual signalling via conspicuous colour patterns.…”