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

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9815365Hairston, Jr.This 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.