Porous species: using gene flow to uncover the genes maintaining behavioral isolation in grasshoppers

• Applicants: Ricardo Pereira, Ph.D.; Professor Dr. Holger Schielzeth
• Subject Area: Evolution, Anthropology ; Systematics and Morphology (Zoology)
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 471413663

The ‘omics’ era reveals an increasing number of species that are practically indistinguishable in morphology, ecology or even in genetics, despite being reproductively isolated from one another in sympatry. While such species complexes present an example of taxonomic conundrum for systematists, they are prized as valuable study systems for evolutionary biologists because the behavioral traits that maintain species boundaries can directly be observed. Here, we propose to study one of such systems, sympatric grasshopper species of the genus Chorthippus that have radiated under pervasive gene flow. This offers opportunities for identifying the genes underlying behavioral isolation and speciation. Using a comparative phylogeographic approach we will test whether species have diverged with ongoing gene flow, or if geographic isolation during glacial periods has facilitated reproductive isolation. Using experimental crosses, we will test for a genetic association between cues and preference of behavioral isolation, which facilitates the maintenance of species boundaries in the face of gene flow. Lastly, using population genomics and behavioral assays, we will test if gene flow has played a role in generating hybrid species that are reproductively isolated from their parentals. This research program will not only offer new insights on how gene flow interacts with sexual selection during species formation, but it will provide a transferable multi-disciplinary approach for taxonomic studies in organisms characterized by large genomes that remain challenging to study.

• DFG Programme: Research Grants