Adaptation to environmental warming? Microevolution in the protists Paramecium and Coleps

各种研究表明，全球变暖将如何影响生态群落的物种多样性。然而，只有几项研究测试了环境变暖可能会如何影响种群的遗传变异，以及这可能会如何改变生态群落中的相互作用。虽然选择实验是解决这些问题的唯一合适的工具，但几乎没有对水生生物进行过选择实验。在这里，我们建议将草履虫作为理想的生物进行实验，以测试全球变暖对种群遗传结构的影响。由于世代时间快，它非常适合这些实验，特别是在冬季平均温度上升的情况下。一个物种内的种群或谱系在多大程度上适应了当时的温度和温度变化，可能对种群在潜在快速变化的热环境下的生存和遗传构成有很大的影响。因此，我们收集了克隆血统的实验种群，这些种群起源于整个欧洲的池塘和溪流种群。使用分子方法，我们能够在选择实验中检测个体谱系。我们将测试a)夏季和冬季平均温度是否升高，以及b)极端温度的增加是否会减少实验种群的遗传变异，以及这种影响是否对溪流种群比池塘种群更强，后者在其自然栖息地经历的温度变化比溪流种群更强烈。最终，我们想要测试由于种群的遗传变化，是否会导致细菌(大肠杆菌)和尾状念珠菌之间的捕食者-猎物关系不匹配。

How global warming will affect the species diversity of ecological communities has been shown in a variety of studies. However, only a few studies have tested how environmental warming may affect the genetic variation of populations and how this might change in turn the interactions in ecological communities. Although selection experiments are an uniquely suited tool to address these questions, almost none have been performed for aquatic organisms. Here we propose to use Paramecium caudatum as an ideal organism to perform experiments, which test the influence of global warming on the genetic structure of populations. Due to fast generation time, it is well suited for these experiments, this is specifically the case for the increase in average winter temperatures. The extent to which populations or lineages within a species are locally adapted to the prevailing temperatures and temperature changes may have strong implications for the population survival and genetic composition under a potentially rapidly changing thermal regime. Consequently, we assemble experimental populations of clonal lineages, which originate from pond and stream populations throughout Europe. Using molecular methods, we are able to detect individual lineages within a selection experiment. We will test a) if elevated average summer and winter temperatures and b) an increase in temperature extremes will reduce the genetic variation of this experimental population and if this effect is stronger for the stream populations than for the pond populations, which experience in their natural habitat stronger temperature changes than the stream populations. Eventually, we would like to test if due to the genetic change of the populations it would come to a mismatch in the predator-prey relationship between bacteria (Escherichia coli) and P. caudatum.