浮游动物对产毒微囊藻抗性的快速进化

The concept of rapid evolution has been shifting the traditional view that ecological and evolutionary processes occupy different timescales. Substantial evolution occurring on ecological timescales affects population persistence, drives speciation or extinction, alters community structure, and shapes ecosystem function. The increased frequency of Microcystis blooms may provide an ideal opportunity for studies of rapid evolution. Since Microcystis can produce toxins, zooplankton as the predators of Microcystis would risk losing both their dinner and their life. Such a special predator-prey interaction has challenged the classical life-dinner hypothesis, which argues that predators experience weaker selection than prey because it is worse to lose life than to miss a dinner. Therefore, we have put forwarded a scientific question: Would zooplankton rapidly evolve resistance to toxic Microcystis?.First, the resistance variations among zooplankton populations from either Microcystis bloom areas or non-bloom areas will be investigated using the geographic mosaic theory. Then, the trajectory of evolution in zooplankton resistance to toxic Microcystis will be traced using the artificial selection theory. Finally, a historical population prior to the occurrence of Microcystis blooms will be constructed using the zooplankton resting egg bank theory and the resistance difference between the historical and present populations will be compared..The goal of the present study is to test the hypothesis that zooplankton can rapidly evolve resistance to toxic Microcystis from three points of geographic variation, artificial selection, and sediment record. The results would explore the presence of rapid evolution in pelagic ecosystem and provide new insights into the mechanisms of zooplankton adaptations to eutrophication.

"快速进化"正逐步改变生态过程与进化过程不重叠的传统观点，微囊藻水华的频繁暴发很可能为该研究提供了一个崭新的机遇。微囊藻能够产生毒素，作为捕食者的浮游动物将面临失去食物和生命的双重压力，这也挑战了经典的"生命晚餐假说"。因此，本项目提出关键科学问题：浮游动物能否快速进化出对产毒微囊藻的抗性？.本项目将利用地理马赛克理论比较微囊藻水华区与非水华区浮游动物对产毒微囊藻的抗性差异；利用人工定向选择理论追踪浮游动物抗性的进化轨迹；利用浮游动物休眠卵库理论重建浮游动物在微囊藻水华暴发前的历史种群，并比较其与现代种群的抗性差异。.本项目的预期目标是从地理变异、人工选择、沉积记录三个方面系统验证浮游动物对产毒微囊藻抗性快速进化的科学假说，探索快速进化现象在浮游生态系统中的存在和效应，为阐明浮游动物对水体富营养化的适应机制提供新思路和理论支撑。

快速进化能够影响种群可持续性，加速物种分化速度，改变物种灭绝轨迹，重组生物群落结构，调节生态系统功能。虽然快速进化研究在学术界已经初现端倪，但水生环境中的相关研究非常稀少，研究体系的局限性阻碍了我们对快速进化现象的全面认识。本项目以我国微囊藻水华的频繁暴发为切入点，提出了关键科学问题：浮游动物能否快速进化出对产毒微囊藻的抗性？. 本项目综合运用了地理马赛克理论、人工定向选择理论、浮游动物休眠卵库理论，从地理变异、人工选择、沉积记录三个方面系统验证了浮游动物对产毒微囊藻快速进化的科学假说。本项目还新增加了浮游动物对产毒微囊藻的诱导防御和母体效应、产毒微囊藻对浮游动物竞争格局的逆转效应两方面研究。主要研究结果有：发现浮游动物对微囊藻的诱导防御，并定量其收益和代价；发现浮游动物对微囊藻诱导防御具有母体效应；发现浮游动物单个种群内部存在对微囊藻抗性在的巨大变异；发现浮游动物通过降低生长可塑性增强对微囊藻的抗性；发现微囊藻毒性和捕食作用共同导制浮游动物群落小型化；发现浮游动物母体状态影响后代对微囊藻的抗性；阐明浮游动物温度反应模式及其影响因素；发现微囊藻逆转浮游动物种间竞争结果；发现微囊藻水华、水体缺钙和增温对浮游动物适合度的复合作用；发现浮游动物对微囊藻的局域适应；发现低钙和微囊藻反转浮游动物种间竞争；发现浮游动物对产毒微囊藻抗性的快速实验进化；解读浮游动物对产毒微囊藻快速响应的沉积记录。. 研究结果丰富了对生态过程与进化过程相互作用的探索和认知，揭示了快速进化现象在浮游生态系统中的存在和效应，为阐明了浮游动物对水体富营养化的适应机制提供了新思路和理论支撑。项目负责人以独立通讯作者发表SCI源刊论文13篇，其中一区期刊1篇、二区期刊6篇。在本项目的支持下，已毕业6名研究生（3名获得研究生国家奖学金）；项目负责人荣获首届“优秀青年动物生理生态学工作者”称号。