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Research article2023Peer reviewed

Species divergence under competition and shared predation

Roesti, Marius; Groh, Jeffrey S.; Blain, Stephanie A.; Huss, Magnus; Rassias, Peter; Bolnick, Daniel I.; Stuart, Yoel E.; Peichel, Catherine L.; Schluter, Dolph

Abstract

Species competing for resources also commonly share predators. While competition often drives divergence between species, the effects of shared predation are less understood. Theoretically, competing prey species could either diverge or evolve in the same direction under shared predation depending on the strength and symmetry of their interactions. We took an empirical approach to this question, comparing antipredator and trophic phenotypes between sympatric and allopatric populations of threespine stickleback and prickly sculpin fish that all live in the presence of a trout predator. We found divergence in antipredator traits between the species: in sympatry, antipredator adaptations were relatively increased in stickleback but decreased in sculpin. Shifts in feeding morphology, diet and habitat use were also divergent but driven primarily by stickleback evolution. Our results suggest that asymmetric ecological character displacement indirectly made stickleback more and sculpin less vulnerable to shared predation, driving divergence of antipredator traits between sympatric species.

Keywords

adaptive divergence; asymmetric interactions; biotic selection; character displacement; sculpin; species interactions; stickleback

Published in

Ecology Letters
2023, Volume: 26, number: 1, pages: 111-123

    UKÄ Subject classification

    Ecology
    Evolutionary Biology

    Publication identifier

    DOI: https://doi.org/10.1111/ele.14138

    Permanent link to this page (URI)

    https://res.slu.se/id/publ/120715