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Evaluation of the Functional Capabilities of Fins and Limbs for Moving on Land: Insights Into the Invasion of Land by Tetrapods" (2014)

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Evaluation of the Functional Capabilities of Fins and Limbs for Moving on Land: Insights Into the Invasion of Land by Tetrapods Clemson University TigerPrints All Dissertations Dissertations 8-2014 Evaluation of the functional capabilities of fins nda limbs for moving on land: insights into the invasion of land by tetrapods Sandy Kawano Clemson University, [email protected] Follow this and additional works at: https://tigerprints.clemson.edu/all_dissertations Part of the Biomechanics Commons, Morphology Commons, and the Zoology Commons Recommended Citation Kawano, Sandy, "Evaluation of the functional capabilities of fins and limbs for moving on land: insights into the invasion of land by tetrapods" (2014). All Dissertations. 1322. https://tigerprints.clemson.edu/all_dissertations/1322 This Dissertation is brought to you for free and open access by the Dissertations at TigerPrints. It has been accepted for inclusion in All Dissertations by an authorized administrator of TigerPrints. For more information, please contact [email protected]. EVALUATION OF THE FUNCTIONAL CAPABILITIES OF FINS AND LIMBS FOR MOVING ON LAND: INSIGHTS INTO THE INVASION OF LAND BY TETRAPODS A Dissertation Presented to the Graduate School of Clemson University In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy Biological Sciences by Sandy Momoe Kawano August 2014 Accepted by: Dr. Richard W. Blob, Committee Chair Dr. Margaret B. Ptacek Dr. Timothy E. Higham Dr. Miriam A. Ashley-Ross Dr. Michael W. Sears ABSTRACT Transitions to novel habitats present different adaptive challenges, producing captivating examples of how functional innovations of the musculoskeletal system influence phenotypic divergence and adaptive radiations. One intriguing example is the transition from aquatic fishes to tetrapods. Recent technological advances and discoveries of critical fossils have catapulted our understanding on how fishes gave rise to terrestrial vertebrates. Considerable attention has been paid to legged locomotion on land, but given that the first tetrapods were aquatic, limbs did not evolve primarily for terrestriality. How, then, is the locomotor function of limbs different from fins? Extant amphibious fishes demonstrate that fins can be used on land, and anatomical analyses of the fish relatives of early stem tetrapods indicate that the appendicular bones of fishes could be quite robust. Consequently, there is a need to evaluate the ability of fins to withstand the physical challenges of terrestrial locomotion in order to shed light on how limbs conferred early stem tetrapods with an upper hand for becoming terrestrial. In the following papers, I have investigated the biomechanical capabilities of different musculoskeletal designs to understand the evolution of terrestrial locomotion in vertebrates. First, I compared the biomechanics of fins and limbs by measuring ground reaction force (GRF) production of mudskipper fishes (Periophthalmus barbarus ) crutching and tiger salamanders (Ambystoma tigrinum ) walking on level ground, two strategies for accomplishing terrestrial locomotion. Yet, tiger salamanders are already terrestrial. In order to ii understand how limbs function in a more habitually aquatic tetrapod, I conducted similar GRF analyses on a semi-aquatic newt ( Pleurodeles waltl ). Once tetrapods moved onto land, a major question is whether locomotion was primarily driven by the forelimbs or the hind limbs. Thus, I evaluated the ability of the forelimbs and hind limbs of A. tigrinum to withstand stresses during terrestrial locomotion. These data provided an opportunity to study whether the bones of different limbs possess different margins of safety against failure. Lastly, I synthesized how extant taxa can be used to model the biology of extinct taxa, advancing our knowledge about how functional innovation of the appendages contributed to one of the greatest revolutions in vertebrate history. iii DEDICATION This dissertation could not have been accomplished without the love, support and encouragement from my father (Itaru), mother (Emilia), and my sister (Sally). My mother and father had to sacrifice their education in order to support their families, and traveled across two continents before they could attain the American dream. Even when we were merely children, our parents engrained upon my sister and me what a privilege it was to obtain an education, and that we could achieve our greatest aspirations with diligence and perseverance. My sister has never ceased to amaze me with her maturity, grace and good nature, and has been there to lend an open heart and a helping hand at my greatest times of need. Thank you for supporting me in all of my endeavors, for being my source of inspiration and encouragement, but most of all, thank you for empowering me to pursue my career aspirations. iv ACKNOWLEDGMENTS I owe my deepest gratitude to the people who assisted me during the many vicissitudes that I experienced on my journey to becoming a scientist. While this relatively short section does not do them justice, I highlighted many of the influential people who supported me throughout the years. As an undergraduate at the University of California, Davis, I worked with some remarkable scientists that shaped the researcher that I am today. Dr. Judy Stamps taught me how to apply an integrative approach for understanding phenotypic variation. Dr. Peter Wainwright introduced me to fish functional morphology and biomechanics, and forever changed how I conducted research. Dr. Roi Holzman challenged me to maintain a competitive edge, and develop projects with broad impacts at the forefront of science. I could not have been as successful in graduate school without my dearest friends and family: Itaru Kawano, Emilia Kawano, Sally Kawano, Kristine Moody, and Drs. Gabe Rivera, Angie Rivera, Emily Kane, Beth Brombosz, Tammy McNutt-Scott, and Glen Scott. They gave me words of advice when I felt lost, gave me hope when I had doubts, and lent me their ears when I needed a friend. I am also grateful for the advisement of my committee: Drs. Rick Blob, Margaret Ptacek, Tim Higham, Miriam Ashley-Ross, Mike Sears, and, previously, Amy Moran. I owe special thanks to Rick for helping me find my “inner paleontologist” and mentoring me, and to Margaret for always looking out for me (including saving me from the monstrous centipede in Hawai’i!). v TABLE OF CONTENTS Page TITLE PAGE ....................................................................................................... i ABSTRACT ........................................................................................................ ii DEDICATION .................................................................................................... iv ACKNOWLEDGMENTS .................................................................................... v LIST OF TABLES ............................................................................................ viii LIST OF FIGURES ........................................................................................... ix CHAPTER I. INTRODUCTION ............................................................................... 1 References ................................................................................. 11 II. PROPULSIVE FORCES OF MUDSKIPPER FINS AND SALAMANDER LIMBS DURING TERRESTRIAL LOCOMOTION: IMPLICATIONS FOR THE INVASION OF LAND ......................................................................................... 15 Abstract ...................................................................................... 15 Introduction ................................................................................. 17 Materials and Methods ............................................................... 24 Results ....................................................................................... 29 Discussion .................................................................................. 34 Acknowledgments ...................................................................... 43 References ................................................................................. 44 III. PROPULSIVE FORCES OF THE SEMI-AQUATIC NEWT, PLEURODELES WALTL : INSIGHTS INTO THE FUNCTIONAL EVOLUTION OF TERRESTRIAL LOCOMOTION IN EARLY STEM TETRAPODS ........................ 50 Abstract ...................................................................................... 50 vi Table of Contents (Continued) Page Introduction ................................................................................. 51 Materials and Methods ............................................................... 58 Results ....................................................................................... 62 Discussion .................................................................................. 70 Acknowledgments ...................................................................... 77 References ................................................................................. 79 IV. COMPARATIVE LIMB BONE LOADING IN THE FORELIMBS AND HIND LIMBS OF THE SALAMANDER AMBYSTOMA TIGRINUM: TESTING THE “MIXED-CHAIN” HYPOTHESIS FOR SKELETAL SAFETY FACTORS ........................................ 83 Abstract ...................................................................................... 83 Introduction ................................................................................. 84 Materials and Methods ............................................................... 89 Results ..................................................................................... 102 Discussion
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