HOW ECOLOGY AND EVOLUTION SHAPE SPECIES DISTRIBUTIONS AND ECOLOGICAL INTERACTIONS ACROSS TIME AND SPACE by IULIAN GHERGHEL Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Advisor: Ryan A. Martin Department of Biology CASE WESTERN RESERVE UNIVERSITY January, 2021 CASE WESTERN RESERVE UNIVERSITY SCHOOL OF GRADUATE STUDIES We hereby approve the dissertation of Iulian Gherghel Candidate for the degree of Doctor of Philosophy* Committee Chair Dr. Ryan A. Martin Committee Member Dr. Sarah E. Diamond Committee Member Dr. Jean H. Burns Committee Member Dr. Darin A. Croft Committee Member Dr. Viorel D. Popescu Date of Defense November 17, 2020 * We also certify that written approval has been obtained for any proprietary material contained therein TABLE OF CONTENTS List of tables ........................................................................................................................ v List of figures ..................................................................................................................... vi Acknowledgements .......................................................................................................... viii Abstract ............................................................................................................................. iix INTRODUCTION............................................................................................................. 1 CHAPTER 1. POSTGLACIAL RECOLONIZATION OF NORTH AMERICA BY SPADEFOOT TOADS: INTEGRATING NICHE AND CORRIDOR MODELING TO STUDY SPECIES’ RANGE DYNAMICS OVER GEOLOGIC TIME ............................ 5 Abstract ............................................................................................................................... 5 Introduction ......................................................................................................................... 6 Materials and Methods ........................................................................................................ 9 Study organism ............................................................................................................ 9 Species occurrence data ............................................................................................... 9 Climatic variables ...................................................................................................... 10 Ecological niche modeling ........................................................................................ 11 Estimating dispersal patterns and migration corridors .............................................. 13 Testing the dispersal and migration corridor estimates with independent data ........ 14 Results ............................................................................................................................... 15 Ecological niche models performance and estimated present distributions .............. 15 Past distributions and glacial refugia ......................................................................... 16 i Identifying the likely migration corridors used to migrate from LGM refugia to extant ranges ..................................................................................................................... 17 Testing dispersal patterns using genetic data: a case study in Spea hammondii ....... 17 Discussion ......................................................................................................................... 18 Species distribution models: past and present distributions ...................................... 19 Using population genetic data to test our results ....................................................... 20 The role of dispersal .................................................................................................. 21 CHAPTER 2. BIOTIC INTERACTIONS VARY ACROSS SPECIES’ RANGE AND ARE LIKELY CONSERVED THROUGH GEOLOGICAL TIME ................................ 27 Abstract ............................................................................................................................. 27 Introduction ....................................................................................................................... 28 Material and Methods ....................................................................................................... 31 Model system ............................................................................................................ 31 Species occurrences ................................................................................................... 32 Environmental data .................................................................................................... 34 Modeling approach .................................................................................................... 35 Post-processing methodology .................................................................................... 36 Results ............................................................................................................................... 37 Model performance summary ................................................................................... 37 Fairy shrimp (prey) distribution patterns in the context of predator species ranges . 38 ii Correlation between the distribution of fairy shrimp and spadefoot toads across spatial scales...................................................................................................................... 39 Discussion ......................................................................................................................... 40 Presence of prey resources in time are important for patterns of predator co- occurrence ......................................................................................................................... 41 Spatial variation in prey-predator relationships ........................................................ 43 Biotic interactions in species distribution modeling ................................................. 44 CHAPTER 3. THE ECOLOGICAL AND SELECTIVE EFFECTS OF RESOURCE POLYPHENISM ON LOWER TROPHIC LEVELS ...................................................... 51 Abstract ............................................................................................................................. 51 Introduction ....................................................................................................................... 52 Materials and Methods ...................................................................................................... 54 Study system .............................................................................................................. 54 Effects of resource polyphenism ............................................................................... 57 Microcosm experiment .............................................................................................. 57 Mesocosm experiment ............................................................................................... 59 Statistical analyses ..................................................................................................... 61 Results ............................................................................................................................... 63 Microcosm selection experiment ............................................................................... 63 Mesocosm experiment ............................................................................................... 65 iii Discussion ......................................................................................................................... 66 Effects of trophic plasticity on the strength of selection ........................................... 67 Effects of trophic plasticity on the reproductive traits .............................................. 67 Effects of trophic plasticity on ecosystem functioning ............................................. 69 Appendix for Chapter 3 .................................................................................................... 78 CONCLUSIONS ............................................................................................................. 82 BIBLIOGRAPHY ........................................................................................................... 84 iv LIST OF TABLES Chapter 1 Table 1.1…………………………………………………………………….23 Chapter 2 Table 2.1…………………………………………………………………….46 v LIST OF FIGURES Introduction Figure 1……………………………………………………………………..…2 Chapter 1 Figure 1.1…………………………………………………………………….24 Figure 1.2…………………………………………………………………….25 Figure 1.3…………………………………………………………………….26 Chapter 2 Figure 2.1…………………………………………………………………….47 Figure 2.2…………………………………………………………………….48 Figure 2.3…………………………………………………………………….49 Figure 2.4…………………………………………………………………….50 Chapter 3 Figure 3.1……………………………………………………………………71 Figure 3.2…………………………………………………………………….72 Figure 3.3…………………………………………………………………….73 Figure 3.4…………………………………………………………………….74 Figure 3.5…………………………………………………………………….75 Figure 3.6…………………………………………………………………….76 vi Figure 3.7…………………………………………………………………….77 vii ACKNOWLEDGEMENTS There are many people to which I would like to thank for supporting and helping me. First, I must thank to my advisor Ryan Martin, that helped, guided and believed in me along the five-year tenure that I was in his lab. I would also want to express my appreciation to my