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Durham E-Theses The relationship between developmental stability, Ggenomic diversity and environmental stress in two cetacean species:: the Harbour Porpoise (Phocoenaphocoena) and The Bottlenose Dolphin (Tursiops truncatusl) Lopez, Carlos Julian De Luna How to cite: Lopez, Carlos Julian De Luna (2005) The relationship between developmental stability, Ggenomic diversity and environmental stress in two cetacean species:: the Harbour Porpoise (Phocoenaphocoena) and The Bottlenose Dolphin (Tursiops truncatusl), Durham theses, Durham University. 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Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk 2 The Relationship between Developmental Stability, Genomic Diversity and Environmental Stress in Two Cetacean Species: The Harbour Porpoise {Phocoena phocoena) and The Bottlenose Dolphin (Tursiops truncatus). A copyright of tlhns thesis rests witlhl tfrne author. No quotation fmm it sluouDd be n>ulOHslhledl wUihlm!t his n>rior wriUellll collllSellllt by all]dl illllformatiol!ll derived from it should ll>e adrnow~edged. Carlos Julian De luna lopez Submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy at University of Durham School of Biological and Biomedical Sciences 2005 Declaration The material contained within thus thesis has not been previously submitted for a degree at the University of Durham or any other university. The research reported here has been conducted by the author unless indicated otherwise. The copyright of this thesis rests with the author. No quotation from it should be published without his prior written consent and information derived from it should be acknowledged. I II Abstract The relationship between developmental stability, genomic diversity and environmental stress in three eastern North Atlantic populations of the harbour porpoise (Phocoena phocoena), and in two populations of the western North Atlantic and one from the Gulf of California of the bottlenose dolphin ( Tursiops truncatus) was investigated. In addition, the population structure for the two species from the study areas mentioned was also assessed. Population structure was determined using discriminant function analysis for morphological characters and a Bayesian analysis for microsatellite loci. Consistency of the results was assessed with pairwise comparisons between populations using two indices of population differentiation (FsT and RhosT). For the harbour porpoises classification was made into three putative populations: Norwegian, British and Danish. For the bottlenose dolphin significant differentiation was found for the three populations studied. Population differentiation between the two western North Atlantic parapatric populations was the highest among the pairwise comparisons. This result highlights the importance of resource specialisation of bottlenose dolphins in causing population structure for parapatric populations. Developmental stability was assessed by fluctuating asymmetry (FA) measured on morphological traits. Genomic diversity was determined by five indices (mean cf, scaled mean cf, multilocus individual heterozygosity, standardised heterozygosity and internal relatedness). Environmental stress was assessed by the concentration of chemical pollutants in tissues, and from the literature published for chemical pollutants, by-catch rate, parasite load and mean surface ocean temperature. Significant relationships between FA and the indices of genomic diversity were Ill found. The Norwegian population of harbour porpoises and the coastal population of the western North Atlantic of bottlenose dolphin showed the highest level of FA. Both populations also showed the least genetically diverse animals. However, no clarity was obtained in respect of the relationship between FA and environmental stress. British and Norwegian harbour porpoises did not show significant correlations between the concentration of several chemical pollutants in tissues and FA. In addition, the Norwegian population of harbour porpoise inhabits the least impacted areas in respect to the concentration of chemical pollutants in tissues, parasite load and by-catch rates. Environmental stress was difficult to assess on the bottlenose dolphins populations due to the scarcity of data. These results show the influence of genetic diversity on the disruption of developmental stability and they also show the importance of conservation practices in maintaining genetic diversity as an important factor for the subsistence of natural populations. IV Dedicatory I dedicate this thesis to my wife Adriana and my son Adrian. Adriana without your immense love and huge support I would not have finished this phase. Thank you very much for your unconditional love and for all your support throughout these years. You chose to venture with me in this journey and I really appreciate the fact that you are always by my side. Thank you, wife. Adrian, I know that you are too young to understand these words. Everyday I thank God that you are my son. I always looked forward to finishing my day in the lab so I could arrive home and spent some time with you. Thank you for always seeing the good things inside the bad. To you both I am deeply in debt. I also want to dedicate this to my Mom, Dad, my sister, my brother and their beautiful families. You always give love and support even when we are apart. Thank you. v Acknowledg1nents During the four years that I spent working in this project I have known very helpful and interesting people. I will do my best to acknowledge them. First, I thank my supervisor Dr. A. R. Hoelzel, for all his guidance and patience during all this years. It is difficult to make a veterinarian think in an evolutionary perspective, however somehow, you have achieved this. I can tell now that, thanks to you I have a better understanding in the field of molecular ecology. Thanks to all the people in the Molecular Ecology Laboratory Group. I consider myself fortunate that I was surrounded with so many talented people. I thank Dimitris, Anna, Courtney, Stefania, Dan, Eulalia and David for sharing their knowledge and friendship. Very special thanks go to Ada and her lovely family for all her support during all this phase. To Ana T6pf for her help in extracting DNA from bones and teeth. To Fiona Lovatt and Colin Nicholson for all the support during my early days in the lab. To Pia Anderwald for her support in obtaining mean ocean surface temperatures and her friendship. Thanks to Vittoria Elliott for her invaluable help in the last days. To Andy Foote and Laura Corrigan I want to thank them for their dear friendship and invaluable support, thanks Andy for your comments on early drafts of this thesis. To my great Italian friend Diletta Castellani for her beautiful friendship, great chat, and for setting an example of perseverance. And, of course to my dear Valentina Islas which made Durham a very enjoyable place for some time, I miss you friend. I also thank Hadil and Sanji for their friendship and support. To you guys thank you very much. This study would not have been possible without the assistance and help of the authorities of the museums visited. I thank 0ystein Wiig from the Zoologisk Museum, University of Oslo. Paula Jenkins and specially Richard C. Sabin from the Natural History Museum in London. Andrew Kitchener and specially Jerry Herman from the National Museums of Scotland in Edinburgh. Carl Christian Kinze from the Zoologisk Museum, University of Copenhagen. Fernando Cervantes from the Coleccion Nacional de Mamiferos, Mexico City; and Charles W. Potter from the National Museum of Natural History-Smithsonian Institution, Washington D.C. (Thanks to 0ystein and Richard for their friendship). VI I thank Oliver Thatcher, Simon Goodman and Liselotte W. Andersen for their support in providing some genotypes. Thanks to Paul Jepson of the Institute of Zoology and Robin J. Law from CEFAS, UK for providing some of the environmental data. I also thank Bruna Pagliani for her support, but mainly for breaking the monotony during long hours of measuring skulls while in Washington. I really miss you. Thanks to Nils 0ien for all his assistance during the export of the Norwegian samples. I want to express my gratitude to CONACYT (National Council for Science and Technology, Mexico) for the financial support during these four years. Last but not least, I want to express my deeply gratitude to Krystal A. Tolley. I do not have the honour to personally know you, however you have been very useful during this phase, I appreciate all your e-mails and advice and the access to the information. I admire what you do. To all of you thanks again. VII Table of Contents Declaration ii Abstract iii Dedicatory v Acknowledgements vi List of tables XV List of figures xviii Chapter 1: General Introduction 1 Thesis aims 13 Chapter 2: Population structure in the eastern North Atlantic population of the Harbour Porpoise (Phocoena phocoena). 14 2.1. Introduction 14 2.1.1. Population structure around Norwegian waters 16 2.1 .2. Population structure around Danish waters 18 2.1.3. Population structure around British waters 18 2.2. Methods 19 2.2.1. Cranial measurements 19 2.2.1 .1 . Sample collection 19 2.2.1.2. Choice of traits 19 2.2.2 Microsatellite analyses 22 2.2.2.1. Samples obtained and previously published data used 22 2.2.2.2.