Séminaire de Claire DUFOUR (Harvard University)


Le vendredi 26 octobre 2018 à 13h00, salle de conférences de l'OSUR, bâtiment 14b, Campus de Beaulieu, UR1

Le vendredi 26 octobre 2018 à 13h00, salle de conférences de l'OSUR, bâtiment 14b, Campus de Beaulieu, UR1

Interaction between ecological and agonistic character displacements in Anolis lizard: a new avenue in interspecific competition research

Abstract: Invasive species are a global scourge. Nonetheless, they provide the appropriate evolutionary setting to rigorously test the role that interspecific competition plays in species evolution. The introduction of Anolis cristatellus to Dominica, a Caribbean island where Anolis oculatus—a closely related native species—occurs, offers a rare opportunity to study the coexistence processes at fine spatial and temporal scales. With an empirical approach in the field, we considered simultaneously the role of resource-use and interference competitions in the evolution of ecological, behavioral, morphological and performance traits by comparing populations in area where the species are present either alone (allopatry) or co-occur (sympatry). We revealed the presence of a two-step ecological character displacement: in sympatry, habitat divergence occurred rapidly but was associated with morphological divergence only after decade(s) of coexistence (Dufour, Herrel & Losos, 2017). In areas where the two species came into contact only few years ago, we then demonstrated a communication behavioral shift in the invasive species related to indirect or direct competition (Dufour, Herrel & Losos, 2018). Finally, thanks to realistic lizard robots, we simulated interference competition in natura and determined the presence of a rapid agonistic character displacement in display behavior of the native species. Evolutionary biologists have often considered behavior as an inhibitor of evolutionary change. This study demonstrates, however, that behavioral change may directly alter selective pressures as being a first response to recent interspecific competition and highlights its importance in understanding species invasion in action.

Contact: Claire DUFOUR