PRSL - Genetic architecture of adaptive radiation across two trophic levels In most young fish radiations, transitions between invertivory and herbivory are unusual. Haplochromine cichlid fish of the African Great Lakes are exceptional in this regard. Lake Victoria was colonized by an insectivorous generalist and in less than 20 000 years, several clades of specialized herbivores evolved. Anna and Ole investigated components of the genetic architecture of a suite of traits that distinguish invertivores from algae scrapers by QTL mapping based on a second-generation hybrid cross. There were indeed indications of linkage/pleiotropy within trait complexes. However, QTLs for distinct traits were distributed across several unlinked genomic regions. Thus, a mixture of independently segregating variation and some pleiotropy may underpin the rapid trophic transitions.