Interest in the evolution of invasive species has grown in recent years, yet few studies have investigated sources of variation in invasive species traits experiencing natural selection. The spiny water flea, Bythotrephes longimanus, is an invasive zooplankton in the Great Lakes that exhibits seasonal changes in tail spine and body length consistent with natural selection. Evolution of Bythotrephes traits, however, depends on the presence and magnitude of quantitative genetic variation, which could change within or across years. Clonal analysis of wild-captured Bythotrephes indicated that variance components for distal spine length were variable among but not within years. Spine length was always heritable but was not always influenced by maternal effects. In contrast, variance components for body length varied both within and among years, but likewise body length was always heritable and not always influenced by maternal effects. Results indicate that important Bythotrephes traits have heritable variation comparable to native species and other invasive species that would enable an evolutionary response to natural selection. This evolutionary capacity could contribute to the widespread success and dramatic effects of Bythotrephes invasion in systems with diverse biotic and abiotic conditions.

Miehls et al. Evol Appl DataThe Miehls et al. Evol Appl Data.csv file contains the data used to quantify genetic, maternal, and environmental variation in distal spine and body length of Bythotrephes longimanus (the spiny water flea) in Lake Michigan (USA). Each row in the spreadsheet includes field and laboratory information (including clonal line relationships and trait measurements) for a single F2 Bythotrephes born in our laboratory clonal lines. All analyses were completed using data from F2 individuals.