Data from: Genetic and maternal effects on tail spine and body length in the invasive spiny water flea (Bythotrephes longimanus)

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.

近年来，学界对入侵物种演化的研究兴趣日益浓厚，但目前鲜有研究聚焦于经受自然选择的入侵物种性状的变异来源。多刺水蚤（Bythotrephes longimanus）是五大湖区域的入侵性浮游动物，其尾棘与体长呈现的季节性变化符合自然选择的作用模式。然而，多刺水蚤的性状演化取决于数量遗传变异的存在与否及其强度，这类变异可能在年内或年际间发生动态变化。对野生捕获的多刺水蚤开展克隆分析后发现，其尾棘远端长度的方差组分仅在年际间存在差异，年内并无显著波动。尾棘长度始终具备可遗传性，但并非总会受到母性效应的影响。与之形成鲜明对比的是，体长的方差组分在年内和年际间均存在差异；同样，体长始终具备可遗传性，但也并非总会受到母性效应的调控。研究结果显示，多刺水蚤的关键性状具备可遗传变异，其水平与本土物种及其他入侵物种相当，这为该物种对自然选择做出演化响应提供了基础。这种演化潜力或许是多刺水蚤能够在多样的生物与非生物环境中成功入侵并产生显著生态效应的重要原因。