DISSERTATION RESEARCH: A genomic and experimental characterization of local adaptation

点击翻译按钮获取中文摘要

Nature provides a mosaic of variability in both abiotic and biotic factors. This often results in populations of a species evolving traits in response to local conditions that give an advantage to individuals in that native habitat but not in other habitats. Understanding the processes that drive such local adaptation is crucial to predicting the fate of species in the face of rapid environmental change. Many species are shifting their ranges to move poleward or to higher altitude sites as temperatures increase, but marine species are also at risk from ocean acidification - the ongoing decrease in ocean pH due to the uptake of carbon dioxide from the atmosphere. This is especially true for marine bivalves, who require specific carbonate chemistry to form their shells. The west coast of North America has natural long-standing variation in ocean pH and temperature; therefore, it is possible that some populations of wide-spread species could contain adaptations that have evolved in areas with low pH and higher temperatures. This may provide insight to scientists on what portions of the genome may be under selection in species during rapid climate warming events or highlight areas of the genome that have adapted to those conditions. The research provides training to a graduate student and additional outreach to commercial, government, non-governmental organizations, and public stakeholders. The proposed research will test whether adaptation to environmental variability has occurred in the Olympia oyster (Ostrea lurida). This ecologically and commercially important bivalve is patchily distributed from southern California up to the central coast of Canada. Using population genomic analyses and common garden experiments, the proposed research will test for adaptive differences among distinct and separate populations from San Francisco Bay, CA, Coos Bay, OR, Puget Sound, WA, and Vancouver Island, British Columbia. Offspring of wild oysters will be raised under common conditions and studied for differences in growth rate, survival, and response to induced stress from temperature and pH. Transcriptomics will be used to characterize cryptic variation in gene expression and identify genes involved in adaptation to theses stressors.