Rapid evolution of an introduced plant Claire Rika Brandenburger Thesis submitted for the degree of Doctor of Philosophy Evolution & Ecology Research Centre School of Biological, Earth and Environmental Sciences UNSW Sydney September 2019 Thesis/Dissertation Sheet Surname/Family Name : Brandenburger Given Name/s : Claire Rika Abbreviation for degree as give in the University calendar : PhD Faculty : Science School : School of Biological, Earth and Environmental Sciences Thesis Title : Rapid evolution of an introduced plant Abstract: Over the last few centuries thousands of species have been introduced to new ranges worldwide, providing excellent opportunities for researchers to study evolution. However, almost all previous studies of evolutionary change in introduced species have compared introduced populations to populations from across the species’ native range, with the result that variation within native ranges likely confounds estimates of evolutionary change. We located the original source population for the South African beach daisy Arctotheca populifolia which was introduced to eastern Australia in the 1930s and set up a common-environment glasshouse experiment to compare four introduced populations with the source population. This provided a precise and powerful method for detecting evolutionary change - and is the first study of its kind investigating a wide range of morphological, physiological, defence and life-history traits in an introduced plant species. In under 90 years introduced A. populifolia has evolved some striking changes. Introduced plants have developed shorter, sprawling bodies and smaller, thicker leaves that are always spoon-shaped instead of developing adult lobes. They employ a lower photosynthetic rate, higher water-use efficiency and lower nitrogen-use efficiency than the source plants. Introduced plants have more ash, alkaloids and leaf hairs than source plants, but are also less tough, with a lower C:N ratio and less phenolics - resulting in no difference in overall defence between source and introduced plants. Finally, introduced A. populifolia has evolved numerous weedy life-history characteristics: more, smaller inflorescences produce more seeds that germinate better, and the plants use a live-fast die-young strategy of germination, flowering and survival - all without needing mates or pollinators. In total, introduced A. populifolia evolved significant changes in 75% of the 41 traits that I measured, making it a very different plant now compared to when it first arrived in Australia. Surprisingly though, I only found evidence to support eight of the 34 evolutionary hypotheses I tested. That is, rapid evolution in introduced species happens, but not always in the direction predicted by theory. The dynamic nature of introduced species demonstrated in this study reveals that the present static approach to understanding and managing introduced species needs to be updated. Declaration relating to disposition of project thesis/dissertation I hereby grant to the University of New South Wales or its agents the right to archive and to make available my thesis or dissertation in whole or in part in the University libraries in all forms of media, now or here after known, subject to the provisions of the Copyright Act 1968. I retain all property rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertation. I also authorise University Microfilms to use the 350 word abstract of my thesis in Dissertation Abstracts International (this is applicable to doctoral theses only). …………………………………………………………… ……………………………………..……………… ……….……………………...…….… Signature Witness Signature Date The University recognises that there may be exceptional circumstances requiring restrictions on copying or conditions on use. Requests for restriction for a period of up to 2 years must be made in writing. Requests for a longer period of restriction may be considered in exceptional circumstances and require the approval of the Dean of Graduate Research. FOR OFFICE USE ONLY Date of completion of requirements for Award: i | Page ORIGINALITY STATEMENT ‘I hereby declare that this submission is my own work and to the best of my knowledge it contains no materials previously published or written by another person, or substantial proportions of material which have been accepted for the award of any other degree or diploma at UNSW or any other educational institution, except where due acknowledgement is made in the thesis. Any contribution made to the research by others, with whom I have worked at UNSW or elsewhere, is explicitly acknowledged in the thesis. I also declare that the intellectual content of this thesis is the product of my own work, except to the extent that assistance from others in the project's design and conception or in style, presentation and linguistic expression is acknowledged.’ Signed ………………………………….. Date ………………… ………………….. COPYRIGHT STATEMENT ‘I hereby grant the University of New South Wales or its agents the right to archive and to make available my thesis or dissertation in whole or part in the University libraries in all forms of media, now or here after known, subject to the provisions of the Copyright Act 1968. I retain all proprietary rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertation. I also authorise University Microfilms to use the 350 word abstract of my thesis in Dissertation Abstract International (this is applicable to doctoral theses only). I have either used no substantial portions of copyright material in my thesis or I have obtained permission to use copyright material; where permission has not been granted I have applied/will apply for a partial restriction of the digital copy of my thesis or dissertation.' Signed ………………………………….. Date …………………………………….. AUTHENTICITY STATEMENT ‘I certify that the Library deposit digital copy is a direct equivalent of the final officially approved version of my thesis. No emendation of content has occurred and if there are any minor variations in formatting, they are the result of the conversion to digital format.’ Signed ………………………………….. Date ………...................……………….. ii | Page STATEMENT OF CONTRIBUTION OF CO-AUTHORS AND DECLARATIONS OF PERMISSION TO PUBLISH. Each chapter has been designed and written as a stand-alone paper for publication in an ecological journal and is self-contained including Introduction, Methods, Results, Discussion, Acknowledgements and References. Therefore, some degree of overlap between chapters is unavoidable. The first person plural ‘we’ and the possessive adjective ‘our’ are used throughout Chapters 1-4 because none of these chapters has been authored by me alone. However, I am the first author on all of the work, having been responsible for the majority of the concepts, data collection, data analyses and writing in each chapter. The contributions by the co-authors for each chapter are listed below. Chapter 1 Rapid reshaping: the evolution of morphological changes in an introduced beach daisy Claire R. Brandenburger, William B. Sherwin, Stephanie M. Creer, Robert Buitenwerf, Alistair G. Poore, Richard Frankham, Patrick B. Finnerty and Angela T. Moles. Published in Proceedings of the Royal Society B, 286, 20181713 (Feb 2019) http://dx.doi.org/10.1098/rspb.2018.1713 ATM conceived the idea. ATM, WBS, RF, and CRB obtained funding. CRB, SC, PF and RB collected data. CRB led the analysis and writing with particular input from WBS and ATM. WBS and AGBP contributed to data analysis. All authors contributed to writing and interpretation. Chapter 2 Rapid evolution of leaf physiology in an introduced beach daisy Claire R. Brandenburger, Julia Cooke, William B. Sherwin and Angela T. Moles. Published in Proceedings of the Royal Society B, 286, 20191103 (Aug 2019) http://dx.doi.org/10.1098/rspb.2019.1103 ATM, CRB, WBS and JC conceived the ideas and designed the methods; CRB grew the plants; JC and CRB collected the data; JC and CRB analysed the data; CRB led the writing of the manuscript. All authors contributed critically to the drafts. iii | Page Chapter 3 Swings and roundabouts: an introduced daisy evolves many changes in defence traits but no overall change in susceptibility to herbivores Claire R. Brandenburger, Martin Kim, Eve Slavich, Floret L. Meredith, Juha-Pekka Salminen, William B. Sherwin and Angela T. Moles. Submitted to Journal of Ecology (July 2019) CRB, ATM and WS conceived the ideas and designed the methodology; CRB grew the plants; CRB, MK, FM and JS collected the data; CRB, ES, ATM and MK analysed the results; CRB led the writing of the manuscript. All authors contributed critically to the drafts. Chapter 4 Weedy and seedy: the rapid evolution of life-history traits in an introduced daisy Claire R. Brandenburger, Ben Maslen, William B. Sherwin and Angela T. Moles. ATM, CRB and WS conceived the ideas and designed the methodology; CRB grew the plants and collected the data; CRB, BM and ATM analysed the results; CRB led the writing of the manuscript. All authors contributed critically to the drafts. iv | Page INCLUSION OF PUBLICATIONS STATEMENT UNSW is supportive of candidates publishing their research results during their candidature as detailed in the UNSW Thesis Examination Procedure. Publications can be used in their thesis in lieu of a Chapter if: • The student contributed greater than 50% of the content in the publication and is the ‘primary