|Title / Titel||Adaptation and phylogenetic inertia in amphibian phenotypic design|
|Abstract (PDF, 14 KB)|
|Summary / Zusammenfassung||Perspectives on adaptation and optimality have swept in and out of favor over the decades, yet the study of adaptation remains important in all areas of ecology and evolution. We know that many traits are beneficial, but that does not mean they are optimal. Indeed, there is much evidence for maladaptation. The main area of disagreement is the relative strengths of the optimizing force of selection and the processes that oppose selection. These opposing processes include random drift, multivariate selection, and phylogenetic inertia (the tendency of a trait to resist current selection).
This project addresses the question: Do organisms express mostly optimal traits, or are they somehow prevented from reaching optimality? Does the answer differ for different kinds of traits?
This question will be addressed in a comparative study of European anuran larvae (frogs and toads). I have previously reared tadpoles of 11 species in outdoor mesocosms, using well-developed and standardized methods. During a single field season (2011), I will expand the experiments to include 14 additional species, bringing the total sample to 25 species covering >70% of mainland European anuran diversity. The experiments include three treatments (no predators, dragonfly larvae, and fish), and a variety of traits will be measured reflecting tadpole behavior, color, morphology, and life history. Quantitative information on habitats and evolutionary relationships is available from other sources. Analyses will evaluate the relative strength of evidence for adaptation and phylogenetic inertia in trait means, and in predator-induced plasticities. I will also check for correlated evolution among traits, between induced responses to different environments, among plasticities and trait means, and between the multivariate directions of species divergence and ancestral levels of plasticity.
Adaptive explanations are once again popular in evolutionary biology, yet comparative work is turning up convincing evidence of phylogenetic inertia over surprisingly long spans of time. These two viewpoints need to be reconciled, and my study represents a step in that direction. The results will be important for our most fundamental ideas about organismal design and performance.
|Project leadership and contacts /
Projektleitung und Kontakte
|Funding source(s) /
|SNF (Personen- und Projektförderung)
|Duration of Project / Projektdauer||Oct 2010 to Dec 2011|