Utah State University DigitalCommons@USU All Graduate Theses and Dissertations Graduate Studies 5-2009 Evolutionary Consequences of the Introduction of Eleutherodactylus Coqui to Hawaii Eric Michael O'Neill Utah State University Follow this and additional works at: https://digitalcommons.usu.edu/etd Part of the Biology Commons Recommended Citation O'Neill, Eric Michael, "Evolutionary Consequences of the Introduction of Eleutherodactylus Coqui to Hawaii" (2009). All Graduate Theses and Dissertations. 305. https://digitalcommons.usu.edu/etd/305 This Dissertation is brought to you for free and open access by the Graduate Studies at DigitalCommons@USU. It has been accepted for inclusion in All Graduate Theses and Dissertations by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. EVOLUTIONARY CONSEQUENCES OF THE INTRODUCTION OF ELEUTHERODACTYLUS COQUI TO HAWAII by Eric Michael O'Neill A dissertation submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY in Biology Approved: _________________________ _________________________ Michael E. Pfrender Karen H. Beard Major Professor Research Advisor _________________________ _________________________ Edmund D. Brodie Jr. Karen E. Mock Committee Member Committee Member _________________________ _________________________ Paul G. Wolf Byron R. Burnham Committee Member Dean of Graduate Studies UTAH STATE UNIVERSITY Logan, Utah 2009 ii Copyright Eric M. O'Neill, 2009 All Rights Reserved iii ABSTRACT Evolutionary Consequences of the Introduction of Eleutherodactylus coqui to Hawaii by Eric M. O'Neill, Doctor of Philosophy Utah State University, 2009 Major Professor: Dr. Michael E. Pfrender Department: Biology The introduction of a species to areas outside its native range can result in ecological and genetic changes of evolutionary significance. The frog Eleutherodactylus coqui was introduced to Hawaii, from Puerto Rico, in the late 1980s and has lost genetic variation in mitochondrial DNA. The extent to which founder effects have influenced phenotypic variation in the introduced range is unknown. In this study I compared phenotypic variation in life-history traits, advertisement calls, and stripe patterns among introduced and native populations of the frog Eleutherodactylus coqui . I also conducted laboratory experiments to determine the influence of genetics and temperature on trait variation. Body size in wild populations was positively correlated with elevation in both ranges, but the slope of elevation on body size was greater in Puerto Rico than in Hawaii. Advertisement call frequencies and rates were negatively correlated with elevation but duration was positively correlated with elevation. Frequencies were correlated with body size, but rate, duration, and intensity were not. Color patterns are more variable in Puerto iv Rico than Hawaii and appear to be maintained by balancing selection in Puerto Rico. Lab results indicate that body size is negatively correlated with temperature, which may explain Bergmann's rule in the field, but patterns of intrinsic growth rate may explain differences in the effect of elevation between Hawaii and Puerto Rico. Body size appears to explain most of the variation in call frequencies, whereas temperature explained most of the variation in rate and duration. Color patterns appear to be determined by a single locus with five alleles. Founder effects appear to explain the difference between Hawaii and Puerto Rico in color pattern variation and in clinal variation in body size and call frequencies. The loss of genetic variation in these traits is likely to have evolutionary consequences for this species in Hawaii. (148 pages) v ACKNOWLEDGMENTS I would like to thank Dr. Michael E. Pfrender and Dr. Karen H. Beard, who served as my departmental advisor and research advisor, respectively. Mike's expertise in quantitative genetics and evolution and Karen's expertise in ecology of invasive species were essential to the formation of this research project and to my general understanding of ecology and evolutionary biology. Their complementary areas of proficiency provided me with the necessary resources to develop this dissertation. I am especially thankful to Edmund D. Brodie, who provided much needed laboratory space for carrying out experiments. Additionally, Dr. Brodie heads the Herpetology Group at Utah State University, whose meetings provided invaluable intellectual discussion in areas including ecology, evolution, systematics, and of course herpetology. I am grateful to Karen Mock, who supported me when I was between advisors. She allowed me to work in her molecular laboratory, which provided an opportunity for me to learn new molecular techniques and methods of analysis that have greatly improved my understanding of population genetics. I appreciate the discussions that Paul Wolf and I had about genetics, especially the inheritance of color patterns. I have a special appreciation for my fiancé, Dr. Yukie Kajita. She provided me with so much support during my research that I fear I will never be able to repay her. Hopefully a trip to Hawaii will be a good start. Yukie and I also have two dogs, Justine and Daisy. Their frequent reminders to remove myself from the office and venture out into the wilds of Cache valley were greatly appreciated. vi I would like to thank all the other graduate students with whom I interacted while at Utah State University, especially Trey Simmons, Daniel Mulcahy, Becky Williams, Chris Feldman, Kristin Bakkegard, Alan Spaulding, Jerry and Ali Scoville, Kathleen Pollett, Leigh Latta, Megan Kanaga, Brian Creutzberg, David Galbraith, and many more. For field assistance, I thank my friend Laine Giovenetto who flew to Puerto Rico at his own expense and provided much needed frog capturing skills and moral support. Jesse Poulos was an excellent companion in the field and collected most of the call data in the field and the lab. Nathania Tuttle and Aaron Huff both helped collect frogs. For lab assistance, I thank Gillian Jones, Nathania Tuttle, Leigh Latta, Matt Cooke, Evan Lytle, and Kristin Bakkegard and Katie Latta. Finally, I am grateful to my parents, Ingrid and Leonard, and my sister Christina. Their influences on my life have been profound and I am grateful for their support. Eric M. O'Neill vii CONTENTS Page ABSTRACT ....................................................................................................................... iii AKNOWLEDGMENTS ......................................................................................................v LIST OF TABLES ........................................................................................................... viii LIST OF FIGURES .......................................................................................................... xii CHAPTER 1. INTRODUCTION ............................................................................................1 2. CLINAL VARIATION IN NATIVE AND INTRODUCED POPULATIONS OF ELEUTHERODACTYLUS COQUI : LIFE- HISTORY TRAITS ........................................................................................10 3. CLINAL VARIATION IN NATIVE AND INTRODUCED POPULATIONS OF ELEUTHERODACTYLUS COQUI : ADVERTISEMENT CALLS .........................................................................48 4. COLOR PATTERN INHERITANCE AND VARIATION IN NATIVE AND INTRODUCED POPULATIONS OF ELEUTHERODACTYLUS COQUI ............................................................................................................80 5. CONCLUSIONS ..........................................................................................112 APPENDICES .................................................................................................................118 Appendix A. Mean values and standard deviations for adult body size of male and female Eleutherodactylus coqui in Hawaii and Puerto Rico ................119 Appendix B. Mean values and standard deviations for life-history traits in the laboratory .....................................................................................................121 Appendix C. Means and standard deviations for body size and advertisement calls of male Eleutherodactylus coqui in Hawaii and Puerto Rico..............126 Appendix D. Means and standard deviations for body size and advertisement calls in the laboratory ...........................................................................................130 CURRICULUM VITAE ..................................................................................................134 viii LIST OF TABLES Table Page 2.1 Locality data for study populations in Hawaii and Puerto Rico and mean adult body size (SVL) of males and females from each population ..................................35 2.2 NOAA stations used to estimate the relationship between temperature and elevation in Hawaii and Puerto Rico ........................................................................36 2.3 ANOVAs for the effects of source range, site, and elevation on adult body size (SVL) for male and female Eleutherodactylus coqui in Hawaii and Puerto Rico ...........................................................................................................................37 2.4 ANOVAs for the effects of source site and elevation and maternal temperature on clutch size and egg size in the laboratory ............................................................38 2.5 ANOVAs for the effects of source