Rapid evolution mitigates the ecological consequences of an invasive species (Bythotrephes longimanus) in lakes in Wisconsin

Invasive species have extensive negative consequences for biodiversity and ecosystem health. Novel species also drive contemporary evolution in many native populations, which could mitigate or amplify their impacts on ecosystems. The predatory zooplankton Bythotrephes longimanus invaded lakes in Wisconsin, USA, in 2009. This invasion caused precipitous declines in zooplankton prey (Daphnia pulicaria), with cascading impacts on ecosystem services (water clarity). Here, we tested the link between Bythotrephes invasion, evolution in Daphnia and post-invasion ecological dynamics using 15 years of long-term data in conjunction with comparative experiments. Invasion by Bythotrephes is associated with rapid increases in the body size of Daphnia. Laboratory experiments revealed that such shifts have a genetic component; third-generation laboratory-reared Daphnia from ‘invaded’ lakes are significantly larger and exhibit greater reproductive effort than individuals from ‘uninvaded’ lakes. This tr...

外来入侵物种会对生物多样性与生态系统健康造成广泛的负面影响。外来新物种还会驱动诸多本土种群发生当代进化，这种进化或可缓解、亦或加剧其对生态系统的影响。2009年，掠食性浮游动物长肢溞（Bythotrephes longimanus）入侵美国威斯康星州的诸多湖泊。此次入侵导致其浮游动物猎物——水蚤（Daphnia pulicaria）种群出现骤降，并对生态系统服务（水体透明度）产生级联效应。本研究结合15年长期监测数据与对照实验，探究了长肢溞入侵、水蚤进化与入侵后生态动态之间的关联。长肢溞的入侵与水蚤体型的快速增大显著相关。实验室实验表明，此类体型变化具有遗传基础：相较于来自‘未入侵湖泊’的水蚤个体，来自‘已入侵湖泊’的第三代实验室饲养水蚤体型显著更大，且繁殖投入更高。本研究的