Evolutionary impacts on native insects in the GYE

The New Zealand mud snail, Potamopyrgus antipodarum, is an invasive species that causes much concern for the health of Yellowstone’s rivers and streams. Population estimates have been as high as 500,000/m2 in some of the most heavily infected rivers of the greater Yellowstone ecosystem. Studies have shown evidence that P. antipodarum is competing with native invertebrates. Many efforts are being made to address ecological impacts of invasive species but very little effort has been made to address the evolutionary impacts of biological invasions on native species. These evolutionary impacts could affect the native benthic (bottom dwelling) macroinvertebrates in the greater Yellowstone area. Evolutionary impacts could include a change in mandible morphology and overall body size. These consequences may reduce population size or, with sufficient time and genetic variation, lead to evolutionary change in populations of native macroinvertebrates.