Jennifer M. Cocciardi
Project Title: Can species interactions drive rapid niche evolution?
Climate change is causing shifts in species distributions worldwide. Such shifts directly change the composition of ecological communities, resulting in novel biotic interactions. Species will need to rapidly adapt to novel biotic interactions in order to persist, or face extinction. Indeed, such species interactions may be the force necessary to drive evolution of the niche at a rate sufficient to overcome the direct effects of climate change.
Studies examining climate change shifts often neglect potential effects of novel biotic interactions. Those that include biotic interactions do so by investigating the shift and/or adaptation of the realized niche (i.e., niche when interacting with other species). Realized niche shift can result from ecological character displacement (ECD): the process that occurs when two sympatric species diverge away from each other in resource use to mitigate competition. However, there are important questions yet to be resolved: Can ECD evolve at a rate that would mitigate against a rapidly changing climate?
Even more critical, the fundamental niche is the total environmental space that a species is able to occupy and is determined by genetically-based limits hence it is what actually determines how species will survive under a changing climate. If the fundamental niche is able to rapidly adapt and expand outside its current range, this could shed light on a process that may act as a potential buffer to future environmental changes, but this is currently unknown. What we need to know is: Can species interactions cause evolution of the fundamental niche in addition to the realized niche?
My PhD project will use experimental evolution in two rainforest Drosophila species (Drosophila serrata and D. birchii) to determine if species interactions can result in rapid niche evolution to enable coexistence and adaptation to higher temperatures. This study investigates the important conservation question of whether tropical species will be outcompeted and driven to extinction or if rapid niche adaptation will occur when forced to interact with a similar species. In doing so, it will also provide important conceptual advances in understanding niche evolution.
Photo: D birchii female pictured on the left and D. birchii male pictured on the right. D. birchii and D. serrata are sister species with few morphological differences visible to the naked eye.