Recent Topics Posters
Lay, Claire .
Attraction and defense: quandaries of plant sex in geographically distinct populations of Erysimum capitatum.
Plants are stationary organisms that face many simultaneous evolutionary challenges. Among these are selection pressures from both herbivores and pollinators. The effects of these assemblages of selection agents are likely to be antagonistic, and the impacts of each upon plant evolution may be misunderstood by considering them individually. Local adaptation is of particular interest in the context of selection for plant traits by herbivores and pollinators. Interactions between plants, their pollinators and herbivores can be highly site- and time-specific, and plants in different sites have been shown to be under different selection regimes of herbivores and pollinators . This is of particular interest for plant species with generalized pollination systems and a variety of herbivores. Erysimum capitatum is an ideal plant species to answer questions about the joint and separate selective effects of pollinators and herbivores, as well as about local adaptation to different communities of these insects. Floral traits of E. capitatum vary throughout its range, individuals are visited by a wide array of pollinating insects and reproductive tissues are attacked by a number of herbivores. Some of these herbivores could impact pollinator choice. Ants remove nectar from the base of flowers, and occasionally attack bees. Some herbivores, particularly beetle larvae, damage petals, potentially making plants less attractive to pollinators. Also, gall midge larvae (Cecidiomyiidae) form galls from floral buds and typically prevent flowers from opening, which decreases floral display size. Phenotypic characters likely to relate to insect choices as well as insect visitation and herbivory on plants were measured in eight populations over several years. Not all populations were measured in all years, due to low population sizes in some areas in some years. I detected population differences in insect visitation, herbivory and plant phenotypic characters, and these were largely constant among years. Although differences among populations in plant traits and insect visitation/herbivory are not proof of local selection, these differences are indicative of the possibility of local selection.
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1 - University of Colorado, Boulder, Ecology and Evolutionary Biology, N122 Ramaley Hall, Campus Box 334, Boulder, CO, 80309, USA
geographic selection mosaic
Presentation Type: Recent Topics Poster
Location: Event Tent/Cliff Lodge
Date: Tuesday, July 28th, 2009
Time: 5:30 PM