Parasites Lost? An Overlooked Hypothesis for the Evolution of Alternative Reproductive Strategies in Amphibians
Brian
D. Todd
Savannah River Ecology Laboratory, The University of Georgia, Aiken, SC
29802, USA
Abstract
Amphibians exhibit the greatest diversity of reproductive strategies of
all tetrapod vertebrates. While authors have traditionally attributed
the evolution of these strategies to factors such as complex topography,
unpredictable larval environments, and predation on larvae and eggs, support
for any of these hypotheses has been limited. Importantly, most authors
have ignored parasites, including unicellular pathogens and multicellular
parasites, as selective agents capable of influencing amphibian evolution.
Insights in disease transmission, amphibian immunity, and their interaction
with various life histories require that we consider parasites to be selective
pressures in our exploration of the evolution of amphibian reproductive
strategies. I review recent findings and describe how these principles
converge to form a novel conceptual hypothesis for the evolution of alternative
reproductive strategies in amphibians. I offer some specific predictions
and recommend that parasites be considered with other selective pressures
when constructing formal, falsifiable hypotheses during evaluative studies
of amphibian reproductive behavior.
Keywords
anurans, chytrid, disease, iridovirus, life history, salamanders.
SREL Reprint #3049
Todd, B. D. 2007. Parasites Lost? An Overlooked Hypothesis for the Evolution
of Alternative Reproductive Strategies in Amphibians. The American Naturalist
170(5):793-799.
