Evolution of fitness components in the evolving radiation of "sharpfin" sailfin silversides

• Applicant: Dr. Fabian Herder
• Subject Area: Evolution, Anthropology
• Term: from 2010 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 165159114

Understanding the mechanisms forcing speciation remains a major challenge in evolutionary biology. Evolving radiations restricted to habitat islands allow investigating early stages of phenotypic adaptation and associated genomic consequences. The comparatively small but phenotypically diverse radiation of sailfin silverside fish (Atheriniformes: Telmatherinidae) endemic to the ancient Malili Lakes system in Central Sulawesi (Indonesia) has been established as model system for the analysis of speciation processes, and serves here for testing hypotheses on individual fitness consequences of foraging adaptation. Based on a comprehensive random sample of sympatric sharpfin sailfin silversides endemic to isolated Lake Matano, combined acquisition of fitness proxies and multilocus genotyping will allow generating genotypic fitness landscapes of the whole sharpfin species flock. Genomic data will then be used to identify population clusters and potential hybrids. In a next step, a set of morphological key parameters will be quantified from the same fish for generating phenotypic fitness landscapes and for analyzing functional aspects of foraging success. Both landscapes will then be explored in order to describe signature of selection, and will finally be combined to test predictions of the “syngameon” hypothesis of adaptive radiation. Parallel to morphological parameters, courtship coloration will be quantified to account for potential effects of sexual selection in color polymorphic sailfin silversides. Finally, field data describing resource use, competitive regimes and predation risk will be used to relate estimates of selection pressure to selective forces observed in nature.

• DFG Programme: Research Grants