Specialization and performance trade‐offs across hosts in cactophilic Drosophila species
BOUZAS, SANTIAGO; BARBARICH, MARÍA F.; SOTO, EDUARDO M.; PADRÓ, JULIÁN; CARREIRA, VALERIA P.; SOTO, IGNACIO M.
WILEY-BLACKWELL PUBLISHING, INC
Abstract. 1. We assessed the host-related niche breadth for D. koepferae andD. buzzatii, a pair of sibling cactophilic species with contrasting backgrounds of hostuse. We tested for the ?Jack of all trades- Master of none? scenario predicting a moreevident exhibition in D. buzzatii rather than in the supposedly specialist D. koepferae.2. Additionally, using laboratory strains of both species selected for toleranceto extremely high concentrations of a columnar cacti?s secondary metabolites, wetested whether adaptation to a high-demanding host involved the loss of performancecapabilities in other hosts.3. D. buzzatii was more affected by the artificial host shifts than D. koepferae whichpresented an overall better performance when rearing in novel columnar hosts.4. Artificially selected strains of D. buzzatii performed poorer in both novel and nativenatural hosts compared with control strain indicating that adaptation carried associatedcosts regarding the potential to exploit other cacti. Conversely, artificial evolution of theD. koepferae?s strains did not translate into decreased performance in other hosts.5. D. buzzatii complied better with the predictions of the Jack of all trades-Master ofnone hypothesis.6. Host specialization is a dynamic feature in the repleta group and a major driver ofdiversification in its evolutionary history. As the group presents an Opuntia breeder asthe ancestral condition, D. buzzatii would represent not only a plesiomorphic state ofhost use but also the ancestral ecological strategy of specialization.