Collaborative Research: Long Term Diapause and Spreading of Risk Across the Life Cycle.

9903814 Ellner这个研究项目是对允许生物体在随时间变化的环境中生存的特征的调查。 这个问题将探讨两个种群的淡水甲壳类动物（桡足类动物）的经验，每年的变化，在他们生活的湖泊深处。 先前的研究表明，桡足类有两种：一种是长期休眠的，使它们有可能在严酷的环境中生存下来;另一种是在水柱中活动时具有低风险生活史的。 这个项目的问题是，在什么条件下这两种“策略”应该共存，以及拥有它们的生物体是否在遗传上不同。 这项工作包括从湖泊中收集活跃的动物和休眠的卵，并结合实验室繁殖实验。 然后将这些数据与理论预测进行比较，以更全面地了解生物在不断变化的环境中的生存情况。全球环境变化的一个预计影响是气候变化在不同年份之间的增加。 这种时间变化对生物体来说是一个特殊的挑战，因为在一组条件下工作良好的字符可能在另一组条件下不起作用。 根据理论，生物体可能会进化出妥协，或“对冲”的生活史，使它们能够在这种条件下生存。 这个项目的问题是，生物体所具有的特征是否真的是理论所预测的。 答案将有助于理解生物体对环境变化的长期和短期反应。

9903814EllnerThis research project is an investigation of the characteristics that permit organisms to survive in environments that vary though time. This issue will be explored for two populations of freshwater crustaceans (copepods) that experience year-to-year changes in the depths of the lakes in which they live. Previous studies have shown that the copepods are of two kinds: those with a long-term dormancy that makes it possible for them to survive harsh periods; and those possessing a low-risk life history while they are active in the water column. This project asks under what conditions these two "strategies" should be expected to coexist, and whether the organisms possessing them differ genetically. The work involves collections of active animals and dormant eggs from lakes, combined with laboratory breeding experiments. The data will then be compared with theoretical predictions to gain a fuller understanding of organism survival in changing environments.One projected effect of global environmental change is an increase in climate variation among years. This temporal variation is a special challenge for organisms because characters that work well under one set of conditions may not work under another. According to theory, organisms may be expected to evolve compromise, or "bet-hedging" life histories that permit them to survive under such conditions. This project asks if the characteristics organisms possess are in fact those predicted by theory. The answer will help in understanding the long-term and short-term responses of organisms to changing environments.