Pagamea</I> Aubl
Total Page:16
File Type:pdf, Size:1020Kb
University of Missouri, St. Louis IRL @ UMSL Dissertations UMSL Graduate Works 7-27-2007 Pagamea Aubl. (Rubiaceae), from species to processes, building the bridge Alberto Vicentini University of Missouri-St. Louis, [email protected] Follow this and additional works at: https://irl.umsl.edu/dissertation Part of the Biology Commons Recommended Citation Vicentini, Alberto, "Pagamea Aubl. (Rubiaceae), from species to processes, building the bridge" (2007). Dissertations. 578. https://irl.umsl.edu/dissertation/578 This Dissertation is brought to you for free and open access by the UMSL Graduate Works at IRL @ UMSL. It has been accepted for inclusion in Dissertations by an authorized administrator of IRL @ UMSL. For more information, please contact [email protected]. University of Missouri Saint Louis Department of Biology Program in Ecology, Evolution and Systematics Pagamea Aubl. (Rubiaceae), from species to processes, building the bridge by Alberto Vicentini Bolsista do CNPq-Brasil B.S., Forestry Engineering, Universidade Federal do Paraná - Brazil, 1992 Advisory Committee Peter F. Stevens, Ph.D. (Advisor) Elizabeth A. Kellogg, Ph.D. (Co-advisor) Simon T. Malcomber, Ph.D. Paul E. Berry, Ph.D. Patricia G. Parker, Ph.D A Dissertation Submitted to the Graduate School of the University of Missouri - St. Louis in partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in Ecology, Evolution and Systematics with an Emphasis in Evolution January, 2007 @ Copyright 2007 by Alberto Vicentini All Rights Reserved Vicentini, PhD. Dissertation, 2007, UMSL, p. i How long Do works endure? As long As they are not completed. Since as long as they demand effort They do not decay. Inviting further work Repaying participation Their being lasts as long as They invite and reward. Useful works Require people Artistic works Have room for art Wise works Require wisdom Those devised for completeness Show gaps The long-lasting Are always about to crumble Those planned on a really big scale Are unfinished. Still imperfect Like a wall waiting for ivy (It was once unfinished Long ago, before the ivy came; bare) Still short lived Like a machine that is used But not good enough But gives the promise of a better model Work for endurance must Be built like A machine full of shortcomings. ... from “About the Way to Construct Enduring Works” B. Brecht Vicentini, PhD. Dissertation, 2007, UMSL, p. ii ABSTRACT Species delimitation have a great impact in scientific, environmental and other human activities, and is fundamental for understanding evolution. Plant species are usually delimited based on morphology and rarely species concepts are stated and analysis of variation made explicit. Botanists do see species as “segments of evolutionary lineages”, but reproductive isolation is rarely addressed. Yet, reproductive isolation is necessary for understanding species, because speciation is the process of acquiring reproductive barriers. Almost any lineage will have species at different stages of isolation, and a single type of data will be insufficient for species delimitation. In plants, other biological processes such as hybridization, selfing and apomixis, make our search for species more challenging. If one focus on sympatry, reproductive isolation can be inferred, even if species are then defined only locally. If in a single locality putative species are distinct, then they must be reproductively isolated. Here, I first combine molecular phylogenetics (chloroplast and ITS), multivariate analyses of morphology, and sympatry for inferring reproductive isolation and delimiting species in Pagamea, a plant lineage from Tropical South America. I then used phylogenetic estimates of relationships to gain insights into the tempo and mode of speciation in this lineage. The results suggest 29 species in Pagamea. These include monophyletic and paraphyletic species, sympatric but cryptic species, and species that can be recognized only in a local sense. The ITS phylogeny best describes patterns of morphological, ecological and geographical variation, and the chloroplast shows a pattern consistent with the differential sorting of ancestral Vicentini, PhD. Dissertation, 2007, UMSL, p. iii polymorphisms. Pagamea started diversifying ~ 10 million year ago and all speciation events took place before the Pleistocene (>1.5 million years). Data exploration suggests peripatric speciation as the predominant mode in Pagamea, in agreement with the island-like distribution of its specific habitat (white-sand systems). Pagamea diversified along environmental gradients related to both flooding and altitude, with altitudinal shifts being phylogenetically more conserved than shifts for flooding levels. Eight new species of Pagamea are recognized and novel species circumscriptions are made. Hypothesis of species and intraspecific patterns of variation are also made explicit, and several interesting evolutionary scenarios emerge. Vicentini, PhD. Dissertation, 2007, UMSL, p. iv CONTENTS CHAPTER 1 Combining phylogenetics, phenetics and the sympatry criterion for delimiting species in Pagamea Aubl. (Rubiaceae) ............................................................................................1 CHAPTER 2 Tempo and mode of speciation in tropical South America – the case of Pagamea Aubl. (Rubiaceae), a white-sand specialist............................................................................... 83 CHAPTER 3 Revision of Pagamea Aubl. (Rubiaceae) ......................................................................149 Vicentini, PhD. Dissertation, 2007, UMSL, p. v ACKNOWLEDGEMENTS Many, many thanks to Peter Stevens for his advise and unconditional support throughout these years, even when lack of molecular variation, permits, samples or focus suggested no end in sight. Thank you for keeping my feet on the ground and for reading so fast all those preliminary long manuscripts. This work would not have been possible without the discussions about species and systematics…Thanks! Thanks also to Toby Kellogg for sharing her knowledge and for always pointing to the specific questions that clarified my thoughts when I was lost among the many ways a historical work may take. Thanks to Simon Malcomber for sharing data, samples, literature, and, in particular, his expertise about Gaertnera and molecular systematics. Thanks to Paul Berry for samples, for the trips to Venezuela and Suriname, and other opportunities, and for sharing his passion for botany of tropical South America, and the Guayanan flora in particular. Thanks to Patty Parker for her critical insight on the interpretation of the scarce evidence for some of the patterns that emerged from this study. Thanks to all these members of my advisory committee for their comments, questions, and support, especially when I seemed a little lost and not to mention, for having the patience to read this long piece of dissertation. Thanks to former and current members of the Kellogg Lab for discussions, help with lab techniques and for doing my dishes, for contaminating my samples and for keeping the Lab always a pleasant and politically interesting environment….with monkeys and bushes! Special thanks to Janet Barber, Anya Penly, Elma Kay and Jill Preston for all your help. Thanks to Andrew Doust for sharing his samples of Tasmannia, his thoughts Vicentini, PhD. Dissertation, 2007, UMSL, p. vi on doubt and patience, and for his friendship. I loved grinding Setaria! Special thanks to Patrick Sweeney for his computer expertise and for setting up all those nice programs on the cluster. Still in debt with all your help. Thanks to Mark Skippy Belstein for Stereolab and for sharing the hood and the swimming pool those many times. Thanks to Hen Kiser for his friendship and for eating all my food. Thanks to Felipe Zapata, compañero, for papers, readings, and discussions on species, speciation and other things. Thanks to Lucia Lohmann for sharing her enthusiasms with science, for getting samples, sharing papers, and reading previous versions. Thanks also to Anthony Verboom, Bee Gunn, Chris Gillispie, David Kenfack, Jessie Kossuth, Jimena Nores, Lilla Bartkó, Lupita Sanchez, Matt Ogburn , Micah Dunthorn, Mike Zanis, Monica Carlsen, Paulo Camara, Rosa Ortiz-Gentry, Sara Fuentes, Shelby Kleweis and Stevo Refsland. I am grateful to faculty, past and present students and staff from the Biology Department of the University of Missouri Saint Louis, and to all those invisible hands that keep things running there. Special thanks to Bette Loiselle and Patrick Osborne for their trust, and for support through the International Center for Tropical Ecology; also to Maryann Hempen, Pat Hinton and Kathy Burney-Miller for help with so many things. Bob Marquis and John Blake for teachings and sympathy. Kelly Crone for solving problems in the cluster. Mary Rosenthal and Mariette Baxendale for tolerating me as a teaching assistant and still making my life easier. I would like to thank the Missouri Botanical Garden for trusting me the keys to its facilities since my first days in Saint Louis, granting me access to its wonderful Vicentini, PhD. Dissertation, 2007, UMSL, p. vii resources for botanical work, and also for financial help. Special thanks to Mick Richardson for making this possible. Thanks to Charlotte Taylor for literature and for the opportunity to work with the Flora of the Venezuelan Guayana. Trisha Consiglio for help with GIS, Ivan Jimenez for interesting discussions on species and other things -- for their friendship! John Pruski for reading an earlier version