Life History and Population Genetic Structure of Sea Stars from the Family Asterinidae
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LIFE HISTORY AND POPULATION GENETIC STRUCTURE OF SEA STARS FROM THE FAMILY ASTERINIDAE by Carson Keever BSc. University of California Davis 2004 THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY In the Department of Biological Sciences © Carson Keever 2010 SIMON FRASER UNIVERSITY Fall 2010 All rights reserved. However, in accordance with the Copyright Act of Canada, this work may be reproduced, without authorization, under the conditions for Fair Dealing. Therefore, limited reproduction of this work for the purposes of private study, research, criticism, review and news reporting is likely to be in accordance with the law, particularly if cited appropriately. APPROVAL Name: Carson Keever Degree: Doctor of Philosophy Title of Thesis: Life history and population genetic structure of sea stars from the family Asterinidae. Examining Committee: Chair: Dr. Chris Kennedy, Professor ______________________________________ Dr. M. Hart, Professor, Senior Supervisor Department of Biological Sciences SFU ______________________________________ Dr. A. Mooers, Professor Department of Biological Sciences SFU ______________________________________ Dr. F. Breden, Professor Department of Biological Sciences SFU ______________________________________ Dr. B. Crespi, Professor Department of Biological Sciences SFU ______________________________________ Dr. E. Elle, Professor Department of Biological Sciences SFU Public Examiner ______________________________________ Dr. C. Harley, Assistant Professor Department of Zoology UBC External Examiner Date Defended/Approved: December 2, 2010 ii Declaration of Partial Copyright Licence The author, whose copyright is declared on the title page of this work, has granted to Simon Fraser University the right to lend this thesis, project or extended essay to users of the Simon Fraser University Library, and to make partial or single copies only for such users or in response to a request from the library of any other university, or other educational institution, on its own behalf or for one of its users. The author has further granted permission to Simon Fraser University to keep or make a digital copy for use in its circulating collection (currently available to the public at the “Institutional Repository” link of the SFU Library website <www.lib.sfu.ca> at: <http://ir.lib.sfu.ca/handle/1892/112>) and, without changing the content, to translate the thesis/project or extended essays, if technically possible, to any medium or format for the purpose of preservation of the digital work. The author has further agreed that permission for multiple copying of this work for scholarly purposes may be granted by either the author or the Dean of Graduate Studies. It is understood that copying or publication of this work for financial gain shall not be allowed without the author’s written permission. Permission for public performance, or limited permission for private scholarly use, of any multimedia materials forming part of this work, may have been granted by the author. This information may be found on the separately catalogued multimedia material and in the signed Partial Copyright Licence. While licensing SFU to permit the above uses, the author retains copyright in the thesis, project or extended essays, including the right to change the work for subsequent purposes, including editing and publishing the work in whole or in part, and licensing other parties, as the author may desire. The original Partial Copyright Licence attesting to these terms, and signed by this author, may be found in the original bound copy of this work, retained in the Simon Fraser University Archive. Simon Fraser University Library Burnaby, BC, Canada Last revision: Spring 09 ABSTRACT Life history can influence population genetic variation by altering patterns of gamete union and dispersal. Sea stars from the family Asterinidae have evolved similar life histories multiple times in parallel including planktonic feeding larvae, planktonic non-feeding larvae, development in benthic egg masses, and viviparity. In this thesis I first examine the population genetic structure of a widespread planktotrophic asterinid sea star from the East Pacific (Patiria miniata). I use mitochondrial sequence markers to determine whether extrinsic factors such as vicariance or intrinsic properties such as dispersal mode are driving patterns of population genetic variation in this species. I then examine patterns of population genetic variation among eight additional asterinid species from Australia using a mixed species pool of genomic microsatellite markers. I use microsatellite markers to characterize the genetic variation within groups of brooded offspring associated with the unusual life histories of two live bearing asterinids from the genus Parvulastra. Lastly, I examine the evolution of life history among asterinids and use the phylogenetic relationships among species to examine the correlation between life history and population genetic structure in this group. Ultimately, I find that the degree to which intrinsic life history properties of asterinids and extrinsic factors contribute to population genetic iii variation varies among species and among clades. In P. miniata patterns of population genetic variation are influenced by both intrinsic and extrinsic factors. Using microsatellite markers I find that in general between-population genetic variation is high in benthic species (benthic egg laying and live bearing) relative to species with planktonic larvae and that genetic variation within populations is lower in benthic species relative to planktonic species. Lastly, I find that the degree to which phylogeny constrains the coevolution of population genetic structure and life history varies among life history characters and among- population genetic parameters. This thesis suggests that in many cases variation in life histories among a closely related group of marine species can predict patterns of population genetic variation. However, extrinsic factors can in some cases, act with or override life history characteristics in driving patterns of population genetic variation. Keywords: life history, Asterinidae, population genetics, microsatellite marker, comparative method, mating system, brooding iv DEDICATION I would like to dedicate this thesis to Lindy and John Keever, who are the most wonderful parents a girl could ask for, and who have made it possible for me to achieve my goals. v ACKNOWLEDGEMENTS I would like to acknowledge all of the dedicated scientists that have come before me, who have made my research a reality and who have dedicated much of their time to the pursuit of knowledge I would like to especially acknowledge two scientists and mentors who have been an integral part of my scientific career. These include Dr. Richard Grosberg, without whom I wouldn‘t be here, and Dr. Maria Byrne, who has been a supportive and flexible mentor throughout my dissertation. I would also like to acknowledge Dr. Alan Dartnall, one of the pioneers on work in the Asterinidae, who has also been influential in my dissertation success. I would like to acknowledge and thank my senior supervisor Dr. Mike Hart for his patience and understanding throughout this process. The unbiased and unwavering guidance that he provided throughout this thesis has been instrumental in my success. I couldn‘t have asked for a better mentor! I would like to acknowledge my committee for excellent support and guidance at various stages of my studies. Their intellectual contributions were fundamental to the completion of this thesis. I would especially like to thank all of the members of FAB lab who have been so supportive as friends, mentors and peers. I would also like to thank my lab-mates in the Hart lab, Jenn and Susana, I owe them a lot for all of their help, tolerance and friendship through the years. I would like to thank various members of the Toonen lab at the University of Hawaii, especially Jon Puritz, the vi Grosberg lab at UC Davis, especially Brenda Cameron, Jason Addison, Clarissa Sabella, and Melissa Frey and the Byrne lab at the University of Sydney, especially Tom Prowse and Sergio Barbosa. I would also like to thank Christina Zackas, and Lana Roediger who helped me collect samples in Australia, Mary Sewell who helped me collect samples in New Zealand and The Moresby explorers, Shane Anderson and Jon Pierce who helped me collect samples in Haida Gwaii, and California. Finally, I would like to acknowledge my friends and family who have been so supportive throughout this process. I would especially like to thank Mike McDermid and Jenn Sunday who have been wonderful friends to me here in Vancouver; my Parents and my brother Scott, who were always willing and happy to talk about my concerns and insecurities; and to Geoff and Bodi, who are my best friends! vii TABLE OF CONTENTS Approval ...................................................................................................................................... ii Abstract ..................................................................................................................................... iii Dedication ................................................................................................................................... v Acknowledgements ............................................................................................................... vi Table of Contents ...............................................................................................................