title: Introduced Drosophila subobscura populations perform better than native populations during an oviposition choice task due to increased fecundity but similar learning ability.
abstract: The success of invasive species is tightly linked to their fitness in a putatively novel environment. While quantitative components of fitness have been studied extensively in the context of invasive species, fewer studies have looked at qualitative components of fitness, such as behavioral plasticity, and their interaction with quantitative components, despite intuitive benefits over the course of an invasion. In particular, learning is a form of behavioral plasticity that makes it possible to finely tune behavior according to environmental conditions. Learning can be crucial for survival and reproduction of introduced organisms in novel areas, for example, for detecting new predators, or finding mates or oviposition sites. Here we explored how oviposition performance evolved in relation to both fecundity and learning during an invasion, using native and introduced Drosophila subobscura populations performing an ecologically relevant task. Our results indicated that, under comparable conditions, invasive populations performed better during our oviposition task than did native populations. This was because invasive populations had higher fecundity, together with similar cognitive performance when compared to native populations, and that there was no interaction between learning and fecundity. Unexpectedly, our study did not reveal an allocation trade-off (i.e., a negative relationship) between learning and fecundity. On the contrary, the pattern we observed was more consistent with an acquisition trade-off, meaning that fecundity could be limited by availability of resources, unlike cognitive ability. This pattern might be the consequence of escaping natural enemies and/or competitors during the introduction. The apparent lack of evolution of learning may indicate that the introduced population did not face novel cognitive challenges in the new environment (i.e., cognitive "pre-adaptation"). Alternatively, the evolution of learning may have been transient and therefore not detected.
authors.affiliation: Laboratoire Evolution, Génomes, Comportement et Ecologie UMR-CNRS 9191 Gif/Yvette France.
authors.forename: Julien
authors.initials: J
authors.lastname: Foucaud
authors.affiliation: Laboratoire Evolution, Génomes, Comportement et Ecologie UMR-CNRS 9191 Gif/Yvette France.
authors.forename: Céline
authors.initials: C
authors.lastname: Moreno
authors.affiliation: Department of Genetics and IrBio Universitat de Barcelona Av. Diagonal 643 08028 Barcelona Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Pascual
authors.affiliation: Department of Life Sciences University of Roehampton Holybourne Avenue London SW15 4JD UK.
authors.forename: Enrico L
authors.initials: EL
authors.lastname: Rezende
authors.affiliation: Instituto de Ciencias Ambientales y Evolutivas Universidad Austral de Chile PO 5090000 Valdivia Chile.
authors.forename: Luis E
authors.initials: LE
authors.lastname: Castañeda
authors.affiliation: Université de Lyon Université Lyon1 Laboratoire de Biométrie et Biologie Evolutive UMR CNRS 5558 43 Bd du 11 Novembre 1918 69622 Villeurbanne Cedex France.
authors.forename: Patricia
authors.initials: P
authors.lastname: Gibert
authors.affiliation: Laboratoire Evolution, Génomes, Comportement et Ecologie UMR-CNRS 9191 Gif/Yvette France.
authors.forename: Frederic
authors.initials: F
authors.lastname: Mery
keywords: Biological invasion; Drosophila; learning; phenotypic plasticity; trade‐off