Grazing effects of the Invasive Mudsnail, Potamopyrgus antipodarum and Two Native Invertebrates

Although many efforts are being made to address ecological impacts of invasive species, very little effort has been made to address the evolutionary impacts of biological invasions (Sakai eta!. 2001 , Cox 2004). Yet these impacts are likely to be widespread; invasive species have been shown to alter patterns of natural selection or gene flow (Parker et a!. 1999), and many of the best examples of rapid evolution involve invasive species interacting with native species (Reznick and Ghalambor 2001, Strauss et a!. 2006). Hence, I am addressing both the ecological and the potential evolutionary consequences of the invasive New Zealand mud snail, Potamopy rgus antipodarum on native benthic macroinvertebrates in the Greater Yellowstone Area (GY A).