DISSERTATION RESEARCH: The Phylogeny of Poison Dart Frogs (Anura: Dendrobatidae)

American Museum Natural History, New York NY

Investigators

Abstract

A grant has been awarded to Dr. Darrel Frost and Mr. Taran Grant of the American Museum of Natural History to study the evolutionary relationships of poison dart frogs, a family of over 200 species from Central and South America. Investigations over the past 40 years have led to detailed knowledge of many aspects of the biology of these frogs. In contrast, little progress has been made in understanding their phylogeny, which is a minimal requirement for a predictive interpretation of the many discoveries that have been made. This study will undertake a phylogenetic analysis of evidence from mitochondrial and nuclear DNA sequences, morphology, skin toxins, behavior, and vocalizations for approximately 100 species of poison dart frogs and their relatives. The resulting phylogeny will be used to test hypotheses about the evolution of toxicity, habitat preference, vocalizations, and morphological diversification. The phylogeny will also serve to guide natural products chemists by indicating potential sources of alkaloids. The diverse, powerfully toxic alkaloids found in the skin of many poison dart frogs are employed in biomedical research with clear benefits to society. Given that the dietary source of most of these alkaloids remains a mystery, the only source of both known and novel compounds is the frogs. Obtaining and analyzing samples of all species of poison dart frogs is prohibitively costly, but, because the ability to sequester alkaloids is an evolved attribute, the discovery that an untested species is nested within a group of alkaloid-possessing species provides a prediction that the untested species may also possess alkaloids. Furthermore, several species of dendrobatids are critically threatened. Knowledge of dendrobatid phylogeny will allow policy makers to design conservation strategies to protect not only those species known to be toxic, but also any close relatives that have not yet been tested.