23_03_2017, Hyeun-Ji Lee
Título: Eco-evolutionary dynamics and the evolution of phenotypic plasticity Resumen: My research interests lie in how the interaction between the environment and the genotype can shape phenotypic variation within a species. Variation in phenotypic expression can either result from differential gene expression in response to environmental variability (environmentally-sensitive genes) and/or genetic adaptation to the varying environment along a geographical gradient. I am aiming to answer how the interplay of ecological factors and underlying genetic mechanisms give rise to phenotypic expression, and am incorporating an array of study questions and systems in my dissertation. In my first chapter, I am investigating an intriguing case of continental dwarfism in amphibians, focusing on the natterjack toad Epidalea calamita in southern Spain. The dwarf populations in Doñana are about 30% smaller than conspecific populations only about 60 km North, while lacking an efficient geographical barrier. To fully understand the various factors that are driving the intraspecific size variation in this species, I am incorporating standard metabolic rate analysis, stable isotope analysis, skeletochronolgy, male advertisement call description, female behavioral assays, and population genetics using neutral markers. From my second to fourth chapter, I am using the spadefoot toad Pelobates cultripes to study the evolution of phenotypic plasticity. For my second chapter I am raising and conducting water drop experiments on 10 populations of P. cultripes tadpoles, half of which originate from long lasting ponds and half from ephemeral ponds. Those are predicted to have evolved a different capacity to respond to pond desiccation and accelerate development, thus the phenotypic as well as transcriptomic reaction norm will vary across populations. In continuation of this experiment, I am testing the carry-over effects of the environmental challenges experienced in the larval stage in the terrestrial stage in my third chapter. Further, for my fourth chapter, I am planning on exploring the transgenerational effects of the capacity to respond to environmental stress and aim to describe the paternal and maternal effects separately. To do so, I am going to raise my toads to sexual maturity and conduct the water drop experiment on the F1 generation. For my fifth chapter, I am using the waterflea Daphnia magna, a study system that is more readily manipulated in lab conditions due to its fast reproductive cycle. This will allow me to conduct large-scale experiments comprising several generations and populations. I am planning on conducting an experiment on 2 populations of Daphnia, of which only one will receive a predator cue. Subsequently, I will describe how the phenotypically plastic responses of Daphnia have altered the population dynamics and build a model to describe the weight of phenotypic plasticity on population demography.?