Mosquitofish (Gambusia affinis) are a global invader with a tangled history with humanity as agents of biocontrol and models for ecology and evolution. We have studied populations of these fish that have invaded geothermal systems in Aotearoa and California that span a wide temperature gradient. Field surveys, common garden rearing, trait assays, and mesocosm experiments reveal wide-ranging trait variation among populations with ecological effect. Variation in traits are a consequence of interacting plasticity and evolved differences among populations. Evolutionary declines in growth rates and observed body size distributions in the wild reveal evolutionary downsizing in response to warming. Growth and size differences interact with plastic changes in physiological rates to alter metabolic scaling predictions and reduce population energy demand. Ultimately, evolved shifts in body size and plastic shifts in size-linked physiology associated with warming may enable population persistence and cause a range of ecological effects on communities and ecosystem processes.
Kevin Simon is an Associate Professor in the School of Environment at the University of Auckland. He is a freshwater ecologist with broad interests in applied and theoretical ecology. Much of his work revolves around the role that animals play in ecosystem processes. Recent research has focused on how contemporary evolution in the face of thermal change alters the role species play in ecosystems. He and his students also ficus on response of aquatic systems to a range of environmental stressors. Current work in his lab is focusing on the effects of micro-and nanoplastics and ecological processes, interactions between native and invasive organisms, and the effect of urban and agricultural land use on freshwater systems.
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Meeting ID: 261 937 0043