The Role of Developmental Temperature on Phenotypic Development and Evolution Fonti Kar A thesis submitted in fulfilment of the requirements for the degree Doctor of Philosophy Faculty of Science School of Biological, Earth and Environmental Sciences Evolution and Ecology Research Centre December 2020 1 THE UNIVERSITY OF NEW SOUTH WALES Thesis/Dissertation Sheet Surname or Family name: Kar First name: Fonti Other name/s: Shuk Ming Abbreviation for degree as given in the University calendar: PhD School: School of Biological, Earth, and Environmental Sciences; Evolution and Ecology Research Centre Title: The Role of Developmental Temperature on Phenotypic Development and Evolution: Metabolism to Life History Faculty: Science Abstract Animals live in an ever-changing world, but environmental perturbations are occurring at an alarming rate - threatening biodiversity and population persistence. Developmental plasticity may be an effective solution for animals to cope with environmental variation. However, it is unclear how developmental environments affect consistent phenotypic variability and shape individual responses to environmental variation later in life. Understanding these impacts of developmental environments will be important for populations living in fluctuating environments. I employed experimental and comparative approaches to investigate the impacts of incubation temperatures on phenotypic development in an Australian lizard (Lampropholis delicata). Using ‘pace-of-life’ theory as a framework, I investigated how variation in metabolic rate can result in concordant changes in life history. I used a variety of statistical tools to quantify consistent phenotypic variation of energy metabolism and growth. While development temperatures did not affect metabolic rate and its thermal plasticity, lizards reared in hot temperatures exhibited less consistent individual differences in their metabolic rate. This may be problematic in the context for global warming. However, individuals also consistently varied in their acute thermal plasticity and these consistent individual differences were robust to changes in developmental temperatures. This suggests that populations may harbour the ability to evolve suitable responses to a warming climate. Despite there being no developmental changes in metabolism, we found differences in hatching mass that persisted through to the onset of sexual maturity. Growth, and its heritability, were not affected by developmental environments. Instead, maternal effects may play an important role governing variation in growth. While metabolic rate has been purported to be a causal mechanism for variation in life history strategies, I did not find strong support for this hypothesis. Across 500 species of terrestrial ectotherms, I demonstrated that environmental factors that dictate how animals acquire and allocate resources to reproduction are major drivers to life history variation. The environment is comprised of many facets that interact to give rise to the myriad of variation we observe in nature. My thesis highlights the need to shift away from unifying theories and focus on untangling the complexities of the environment in which animals inhabit. that interact to give rise to the myriad of variation we observe in nature. My thesis highlights the need to shift away from unifying theories and focus on untangling the complexities of the environment in which animals inhabit. 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: 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 ..................................................................... INCLUSION OF PUBLICATIONS STATEMENT Acknowledgements First and foremost, I want to express my gratitude and respect to my supervisors Daniel Noble and Shinichi Nakagawa. I’ve worked with Dan since my Masters in 2014 and it has been wonderful to watch our supervisory relationship and friendship evolve over these years. In the beginning, I was a mere naïve student that leaned on Dan a lot but through many years of collaborations, successes and failures, I hope he now considers me as more of a colleague. Dan has always provided me unwavering support. His door was always open for times when I was stuck in my head and needed someone to chat and flesh out my ideas. There were instances throughout my PhD when I was slipping, Dan made sure to check in regularly so that I knew he was there if I needed him. Dan encouraged me to take on tasks that I was perhaps a bit scared to do but these experiences have only trained me to become a more independent researcher. I distinctly remember on several occasions when I was unsure what to do, I said to myself: “What would Dan do?” and proceeded with the task ahead with more confidence. Dan is an enthusiastic teacher, he has a genuine passion for imparting knowledge with anyone who is keen to learn. It never ceases to amaze me the things he’s taught me. From designing experiments and data analysis, to writing papers and programming tricks; to presentation and job interviewing skills. For all of that and more, I am extremely grateful. Over the years of working with Shinichi, I’ve come to find his love for science very contagious. I feel very lucky to have been taught by someone whose knowledge on evolutionary biology, research synthesis and statistical methods is so extensive and vast. Shinichi is very accommodating to my working style and always make the effort to check in despite his busy schedule. I am especially appreciative of the times when Shinichi goes out of his way to help me solve a coding problem or explain the difference between credible and confidence intervals. I’ve always found it strange when people tell me Shinichi is a machine because to me, that is just only one side of him. Shinichi is very encouraging and kind and tries to make everyone feel like they are part of the family. Meeting his Mum for lunch and spending Christmas with him and his 1 family were some of the highlights of my time in his lab. Thank you Shinichi and I hope to continue working with you in the future! I was very lucky to be a part of a very dynamic lab at